A LOOK TO THE FUTURE
Next-Generation Storage concentrating on storing more bits on top of each other.
While most computer chips are written on a single layer
Would you like more storage on your smartphone or tablet to of silicon, Intel’s Optane flash memory uses multilevel
store your photos and videos? Do you use cloud storage ser- cells (MLCs) to store data both horizontally and vertically.
vices to save your files? Have you ever wondered how such Sometimes referred to as 3D flash memory, this nonvola-
services can store so much information? The answer is sim- tile memory promises access speeds that rival traditional
ple—they keep adding hard drives. Magnetic storage methods RAM with the density and price of a traditional hard disk.
are the most common technology for hard drives. The demand In the future, you can expect to see 3D flash memory chips
for larger, cheaper storage is ever
increasing, and researchers are with greater density and lower
exploring new and exotic methods prices.
to store your data. In the future, your
photos and videos may be stored Magnetic disks and flash
using heat, lasers, or even DNA. memory have been storing data
for decades, but scientists are
In traditional hard disks, a mag- looking at new and novel stor-
netic field writes data to a particular age mediums to be the next big
area of the hard disk by flipping the leap in secondary storage. In
magnetic charge to represent a sin- nature, living creatures store
gle bit. The areas to be charged must genetic information on strands
be far enough apart so that when of sequenced cells, called DNA.
one bit is written, the magnetic field In 2014, Harvard researchers
doesn’t bleed over to a neighboring were able to mimic this storage
area and accidentally charge them. medium and stored 704 tera-
Heat-assisted magnetic recording bytes in a single gram of DNA,
(HAMR), a technology being inves- and recently researchers at
tigated by hard-drive manufacturer Columbia University used encod-
Seagate, greatly reduces the required ing techniques developed at
distance between these areas. This Netflix to store 215 petabytes
is accomplished by preheating each in one gram of DNA. Obviously,
area using a precision laser. Once ©ymgerman/Shutterstock the technology to read and write
heated, the surface of the disk DNA data is neither cheap nor
requires less magnetic charge to alter its state. As a result, common, but when it comes to
bleeding is much less of a factor and the distance between the storing data, nature has been doing it longer and better than
charged areas can be greatly reduced, thereby increasing the we have. Perhaps in the future your family photos won’t be
overall capacity of a disk. If this technology can be brought to stored on DVD, but instead on genetic material. Do you think
market, a hard disk could store 50 times more information. that the expenses associated with DNA processing will ever
reduce enough to make DNA data storage useful, or will we
While magnetic disk manufacturers search for ways to continue with hard drives and flash memory?
store more bits on a platter, flash memory researchers are
176
VISUAL SUMMARY Secondary Storage
STORAGE HARD DISKS
–+–– –––+
0 1 00 000 1
A
©wisawa222/Shutterstock Hard disks use rigid metallic platters that provide a large
amount of capacity. They store data and programs by
RAM is primary storage. Most RAM is volatile, meaning altering the electromagnetic charges on the platter’s sur-
that it loses its contents whenever power is disrupted. face. Files are organized according to
Secondary storage provides nonvolatile storage. Second-
ary storage retains data and information after the com- • Tracks—concentric rings on the platter.
puter system is turned off. • Sectors—wedge-shaped sections.
• Cylinders—run through each track of a stack of
Writing is the process of saving information to second-
ary storage devices. Reading is the process of accessing platters.
information. Density refers to how tightly electromagnetic charges
can be packed next to one another on the disk.
Important characteristics include A head crash occurs when the hard disk makes contact
with the drive’s read-write heads.
• Media—actual physical material that retains data and Two types are internal and external hard disks.
programs. Internal Hard Disk
Internal hard disks are located within the system unit.
• Capacity—how much a particular storage medium can Used to store programs and data files.
hold.
• Storage devices—hardware that reads and writes to
storage media.
• Access speed—time required to retrieve data from a
secondary storage device.
Secondary Storage 177
To efficiently and effectively use computers, you need to be aware of the different types of secondary storage. You need
to know their capabilities, limitations, and uses. There are four widely used storage media: hard disk, solid state, opti-
cal disc, and cloud storage.
HARD DISKS SOLID-STATE STORAGE
Source: Courtesy of CalDigit, Inc. ©wk1003mike/Shutterstock
External Hard Drives Solid-state storage devices have no moving parts; provide
Unlike internal hard disks, external hard drives are access to flash memory (solid-state storage).
removable. External drives use the same basic technology
as internal disks. Solid-State Drives
Solid-state drives (SSDs) are similar to internal hard-disk
Performance Enhancements drives except they use solid-state memory; are faster, more
Three ways to improve hard-disk performance are disk cach- durable, and more expensive; and generally provide less
ing, RAID, and file compression and decompression. capacity. Hybrid systems contain SSD and magnetic disks.
• Disk caching—provides a temporary high-speed hold-
Flash Memory Cards
ing area between a secondary storage device and the Flash memory cards are small solid-state storage devices
CPU; improves performance by anticipating data that are widely used with portable devices. They are used
needs and reducing time to access data from second- with a variety of specialized input devices, including digital
ary storage. cameras to store and transfer images and digital media play-
ers like the iPod to store and transfer music and video files.
• RAID (redundant array of inexpensive disks)—several
USB Drives
inexpensive hard-disk drives are connected together; USB drives (flash drives) are so small that they fit onto
improves performance by providing expanded storage, a key ring. These drives connect to a computer’s USB
fast access, and high reliability. port and are widely used to transfer data and information
between computers, specialty devices, and the Internet.
• File compression and decompression—files are com-
pressed before storing and then decompressed before
being used again; improves performance through effi-
cient storage.
©alice-photo/Shutterstock
178 chapter 7
OPTICAL DISCS CLOUD STORAGE
Source: Google and the Google logo are registered trademarks
of Google Inc.
©PhotoDisc/Getty Images With cloud computing, the Internet acts as a “cloud” of
servers. Cloud storage (online storage) is supplied by
Optical discs use laser technology. 1s and 0s are repre- these servers.
sented by pits and lands. Optical disc drives project light
and measure the reflected light. • Cloud servers provide storage, processing, and
The most widely used optical discs are memory.
• Compact discs (CDs) were the first; typical storage • Advantages for users include less maintenance,
700 MB; often used to store music. fewer hardware upgrades, and easy file sharing and
collaboration.
• Digital versatile discs (DVDs) are standard optical
• Disadvantages for users include slower access speed
discs; typical storage 4.7 GB; often used to store
movies and software. and less control over file security.
• Blu-ray discs (BDs) are the newest; designed to MASS STORAGE DEVICES
store hi-def (high-definition) video; typical storage Mass storage refers to the tremendous amount of secondary
25 GB; often used to store hi-def video and video storage required by large organizations. Mass storage devices
games. are specialized high-capacity secondary storage devices.
Each of these optical discs has three basic formats:
Most large organizations have established a strategy
• Read-only (ROM for read-only memory) discs cannot called an enterprise storage system to promote efficient
and safe use of data.
be written on or erased by the user.
Mass storage devices that support this strategy are file
• Write-once (R for recordable) discs can be written on servers, network attached storage (NAS), RAID systems,
and organizational cloud storage. A storage area network
once. After that, they can be read many times but can- (SAN) is a method of using enterprise-level remote stor-
not be written on or erased. age systems as if they were local to your computer.
• Rewritable (RW for rewritable or RAM for random- CAREERS in IT
access memory) discs are similar to write-once discs Disaster recovery specialists are responsible for recovering
except that the disc surface is not permanently altered systems and data after a disaster strikes an organization.
when data is recorded. Bachelor’s or associate’s degree in information systems or
computer science, experience, and additional skills in the
areas of networking, security, and database administration
are desirable. Salary range is $73,000 to $92,000.
Secondary Storage 179
KEY TERMS network attached storage (NAS) (175)
online storage (171)
access speed (165) optical disc (169)
Blu-ray disc (BD) (170) optical disc drive (169)
capacity (165) organizational cloud storage (175)
compact disc (CD) (169) pit (169)
cloud computing (170) platter (165)
cloud storage (171) primary storage (164)
cylinder (165) RAID system (175)
density (165) random-access memory
disaster recovery specialist (175)
digital versatile disc or digital (RAM) disc (170)
read-only memory (ROM) disc (170)
video disc (DVD) (169) recordable (R) disc (170)
disk caching (166) redundant array of inexpensive disks
enterprise storage system (174)
external hard drive (166) (RAID) (167)
file compression (167) rewritable (RW) disc (170)
file decompression (167) secondary storage (164)
file server (175) secondary storage device (164)
flash drive (168) sector (165)
flash memory (168) solid-state drive (SSD) (168)
flash memory card (168) solid-state storage (168)
hard disk (165) storage area network (SAN) (175)
head crash (166) storage device (165)
hi-def (high-definition) (170) track (165)
internal hard disk (166) USB drive (168)
land (169) write-once disc (170)
mass storage (174)
mass storage devices (174)
media (165)
MULTIPLE CHOICE
Circle the correct answer.
1. RAM is sometimes referred to as:
a. primary storage c. read-only memory
b. ratio active memory d. secondary storage
2. The actual physical material that holds the data and programs.
a. primary storage c. capacity
b. media d. access
3. Measures how tightly the magnetic charges can be packed next to one another on the
disk.
a. density c. tracks
b. cylinders d. sectors
180 chapter 7
4. When a read-write head makes contact with the hard disk’s surface, it causes a head:
a. crash c. pit
b. land d. scratch
5. This hard-disk performance enhancement anticipates data needs.
a. disk caching c. file decompression
b. file compression d. RAID
6. This type of storage uses pits and lands to represent 1s and 0s.
a. cloud c. optical
b. hard disk d. solid state
7. DVD stands for: c. dynamic versatile disc
a. digital versatile disc d. dynamic video disc
b. digital video data
8. USB drives are also known as: c. ports
a. flash drives d. universal state bus
b. optical drives
9. An organizational strategy to promote efficient and safe use of data across the networks.
a. cloud dynamic c. enterprise storage system
b. data mission statement d. RAID
10. Specialized high-capacity secondary storage devices designed to meet organizational
demands.
a. CD devices c. mass storage devices
b. flash drives d. platters
MATCHING
Match each numbered item with the most closely related lettered item. Write your answers in
the spaces provided.
a. DVD 1. Provides permanent or nonvolatile storage.
b. file compression 2. Hardware that reads data and programs from
c. hi-def
d. network attached storage media.
3. Concentric rings on a hard-disk platter.
storage 4. Each track is divided into invisible wedge-shaped
e. secondary storage
f. sectors sections called _____ .
g. solid-state drives 5. Increases storage capacity by reducing the amount
h. storage area network
i. storage devices of space required to store data and programs.
j. tracks 6. Optical disc most common on today’s personal
computers.
7. The next generation of optical discs.
8. Similar to internal hard-disk drives except they use
solid-state memory.
9. Mass storage device widely used for home and
small business storage.
10. Architecture to link remote storage devices to
computers such that the devices are as available as
locally attached drives.
chapter 7 181
OPEN-ENDED
On a separate sheet of paper, respond to each question or statement.
1. Compare primary storage and secondary storage, and discuss the most important
characteristics of secondary storage.
2. Discuss hard disks, including density, platters, tracks, sectors, cylinders, head crashes,
internal, external, and performance enhancements.
3. Discuss solid-state storage, including solid-state drives, flash memory, and USB drives.
4. Discuss optical discs, including pits, lands, CDs, DVDs, Blu-ray, and hi-def.
5. Discuss cloud computing and cloud storage.
6. Describe mass storage devices, including enterprise storage systems, file servers, net-
work attached storage, RAID systems, organizational cloud storage, and storage area
network systems.
DISCUSSION
Respond to each of the following questions.
1 Making IT Work for You: CLOUD STORAGE
Have you ever found yourself e-mailing files back and forth between two of your computers or with others
as a way to transport them? Review the Making IT Work for You: Cloud Storage on pages 172–173. Then
respond to the following: (a) Have you ever used Dropbox or a similar service? If so, what service have you
used, and what do you typically use it for? If you have not used Dropbox or a similar service, describe how
and why you might use one. (b) If you do not have a Dropbox account, set up a free one and create a Drop-
box folder. Use Dropbox to either (1) access a file from another computer or (2) share a file with one of your
classmates. Describe your experience. (c) Try a few of Dropbox’s features, and describe your experience
with these features. (d) Do you see yourself using Dropbox on an everyday basis? Why or why not?
2 Privacy: RIGHT TO BE FORGOTTEN
As a generation grows up with social media, a surplus of youthful indiscretions is now stored on the Inter-
net for all to see. Review the privacy box on page 167 and respond to the following: (a) Is there a photo or
video of you on the Internet that you would prefer not be publicly available? Have you said or done things
that, if recorded and posted on social media, could have a negative impact on a job interview? (b) Do you
have the right to decide what photos of you are posted on the Internet by others? Why or why not? (c) Does
someone else have the right to tell you what to do with the photos you take, even if they are in the photo?
Why or why not? (d) Should Facebook remove photos, videos, or messages if someone is embarrassed by
them? Should Facebook have the right to remove your photos, videos, or messages if someone is embar-
rassed by the content? Justify your answer.
182 chapter 7
3 Ethics: CLOUD STORAGE AND CONFIDENTIALITY
When individuals and businesses store files using cloud services, they expect the cloud company to
behave ethically by providing adequate security to protect confidential files. What if this expectation is
not met? Review the Ethics box on page 171, and then respond to the following: (a) Would you be comfort-
able if your attorney stored digital copies of your legal documents in the cloud? What about your doctor
or psychologist? Why or why not? (b) Who should be responsible if files stored in the cloud are stolen
or viewed by hackers or unethical employees? Who would suffer the consequences? Defend your posi-
tion. (c) Should laws be created that require cloud storage companies to operate ethically and to assume
responsibility for security and confidentiality of stored data? Why or why not? (d) Cloud computers are
not necessarily located within the borders of the United States and therefore may not be subject to the
same regulations as U.S.-based computers. Do you think that all U.S. companies should be required to
keep their cloud servers in this country? Defend your response. (e) How do you feel about storing per-
sonal and confidential information in the cloud? Do you currently do it? Why or why not?
4 Environment: SOLID-STATE STORAGE
Did you know that traditional, magnetic hard-disk storage requires more energy than solid-state storage?
Review the Environment box on page 168, and then respond to the following: (a) Why do you suppose
that less energy is required for solid-state drives? (b) Why are not all hard drives being replaced with
solid-state drives? (c) Do you think hard drives will become obsolete in the near future? Why or why not?
(d) Would you be willing to pay more for a solid-state drive? If so, how much? If not, why not?
Design Elements: Concept Check icons: ©Dizzle52/Getty Images; chapter 7 183
Making IT Work for You: ©Shutterstock/cifotart
8chapter Communications
and Networks
©aeyaey/Shutterstock
Why should I read this chapter?
©Alfa Photo/Shutterstock Communication networks are the backbone of nearly every
aspect of modern digital life. In the future, telepresence (the
ability to fully experience the reality of a different place without
actually being there) will be commonplace. For example, doc-
tors will routinely perform surgery on patients located halfway
around the world!
This chapter covers the things you need to know to be pre-
pared for this ever-changing digital world, including:
• Wired networks—learn about coaxial and fiber-optic
cables so you can make smart decisions about home
Internet connections.
• Wireless networks—use your digital devices in smarter and
safer ways by understanding Wi-Fi, satellites, and Bluetooth.
• Mobile computing—become a digital road warrior using
4G and 5G data networks and GPS.
Learning Objectives
After you have read this chapter, you should be able to:
1 Explain connectivity, the wireless revolution, and communication systems.
2 Describe physical and wireless communication channels.
3 Differentiate between connection devices and services, including dial-up, DSL, cable, satellite,
and cellular.
4 Describe data transmission factors, including bandwidth and protocols.
5 Define networks and key network terminology, including network interface cards and network
operating systems.
6 Describe different types of networks, including local, home, wireless, personal, metropolitan, and
wide area networks.
7 Describe network architectures, including topologies and strategies.
8 Explain the organization issues related to Internet technologies and network security.
185
Introduction We live in a truly connected society. We can communicate almost instan-
taneously with others worldwide; changing events from the smallest of
“Hi, I’m Michael, and I’m a network administra- countries and places are immediately broadcast to the world; our e-mail
tor. I’d like to talk with you about computer messages are delivered to handheld devices; cars access the Internet to
communications and networks. I’d also like to receive driving instructions and solve mechanical problems. Even house-
talk about technologies that support mobile hold appliances can connect to the Internet and be remotely controlled.
computing including global positioning sys- The communications and information options we have at our fingertips
”tems, Wi-Fi, and 4G and 5G networks. have changed how we react and relate to the world around us.
©Amble Design/Shutterstock As the power and flexibility of our communication systems have
expanded, the sophistication of the networks that support these systems
has become increasingly critical and complex. The network technologies
that handle our cellular, business, and Internet communications come in
many different forms. Satellites, broadcast towers, telephone lines, even
buried cables and fiber optics carry our telephone messages, e-mail, and
text messages. These different networks must be able to efficiently and
effectively integrate with one another.
To efficiently and effectively use computers, you need to understand the
concept of connectivity, wireless networking, and the elements that make up
network and communications systems. Additionally, you need to understand
the basics of communications channels, connection devices, data transmis-
sion, network types, network architectures, and organizational networks.
Communications
Computer communications is the process of sharing data, programs, and informa-
tion between two or more computers. We have discussed numerous applications that
depend on communication systems, including
• E-mail—provides a fast, efficient alternative to traditional mail by sending and
receiving electronic documents.
• Texting—provides very efficient direct text communication between individuals
using short electronic messages.
• Videoconferencing—provides a very-low-cost alternative to long-distance tele-
phone calls using electronic voice and video delivery.
• Electronic commerce—buying and selling goods electronically.
In this chapter, we will focus on the communication systems that support these and
many other applications. Connectivity, the wireless revolution, and communication
systems are key concepts and technologies for the 21st century.
Connectivity
Connectivity is a concept related to using computer networks to link people and
resources. For example, connectivity means that you can connect your personal com-
puter to other computers and information sources almost anywhere. With this connec-
tion, you are linked to the world of larger computers and the Internet. This includes
hundreds of thousands of web servers and their extensive information resources. Thus,
being able to efficiently and effectively use computers becomes a matter of knowing
not only about connectivity through networks to personal computers, but also about
larger computer systems and their information resources.
186 chapter 8
The Wireless Revolution Figure 8-1 Wireless revolution
The single most dramatic change in con-
nectivity and communications in the past ©fotoinfot/Shutterstock
decade has been the widespread use of
mobile devices like smartphones and tablets
with wireless Internet connectivity. Students,
parents, teachers, businesspeople, and oth-
ers routinely talk and communicate with
these devices. It is estimated that over 2.3 bil-
lion smartphones are in use worldwide. This
wireless technology allows individuals to stay
connected with one another from almost
anywhere at any time.
So what’s the revolution? Although wire-
less technology was originally used primar-
ily for voice communications, today’s mobile
computers support e-mail, web access, social
networking, and a variety of Internet applica-
tions. In addition, wireless technology allows
a wide variety of nearby devices to communicate with one another without any physi-
cal connection. Wireless communications allows you to share a high-speed printer,
share data files, and collaborate on working documents with a nearby co-worker with-
out having your computers connected by cables or telephone. High-speed Internet
wireless technology allows individuals to connect to the Internet and share informa-
tion from almost anywhere in the world. (See Figure 8-1.) But is it a revolution? Most
experts say yes and that the revolution is just beginning.
Communication Systems
Communication systems are electronic systems that transmit data from one location
to another. Whether wired or wireless, every communication system has four basic
elements. (See Figure 8-2.)
• Sending and receiving devices. These are often a computer or specialized commu-
nication device. They originate (send) as well as accept (receive) messages in the
form of data, information, and/or instructions.
• Connection devices. These devices act as an interface between the sending and
receiving devices and the communication channel. They convert outgoing mes-
sages into packets that can travel across the communication channel. They also
reverse the process for incoming messages.
Sending Message Connection Communication Connection Message Receiving
device device channel device device
Packets Communications and Networks 187
Figure 8-2 Basic elements of a communication system
ethics • Data transmission specifications. These are rules and procedures that coordinate
the sending and receiving devices by precisely defining how the message will be
As eavesdropping tools become sent across the communication channel.
more sophisticated, there is
concern that law enforcement • Communication channel. This is the actual connecting or transmission medium
and government agencies will that carries the message. This medium can be a physical wire or cable, or it can be
monitor everyone’s Internet wireless.
and cell phone activity. In the For example, if you wanted to send an e-mail to a friend, you could create and
private sector, companies are
increasingly using network send the message using your computer, the sending device. Your modem, a connection
tools and software to monitor device, would modify and format the message so that it could travel efficiently across
the activity of their employees. communication channels, such as telephone lines. The specifics describing how the mes-
Many websites also track sage is modified, reformatted, and sent would be described in the data transmission
your activity, and government specifications. After your message traveled across the channel, the receiver’s modem,
officials have often requested a connection device, would reformat it so that it could be displayed on your friend’s
these records during the computer, the receiving device. (Note: This example presents the basic communication
course of an investigation. system elements involved in sending e-mail. It does not and is not intended to dem-
Some believe that it is unethical onstrate all the specific steps and equipment involved in an e-mail delivery system.)
for government and businesses
to engage in such monitoring concept check
and tracking. Do you agree?
Define computer communications and connectivity.
What is the wireless revolution?
Describe the four elements of every communication system.
Communication Channels
Figure 8-3 Ethernet cable Communication channels are an essential element of every communication system.
These channels actually carry the data from one computer to another. There are two
Source: Raysonho @ Open Grid categories of communication channels. One category connects sending and receiving
Scheduler/Grid Engine devices by providing a physical connection, such as a wire or cable. The other category
is wireless.
Figure 8-4 Coaxial cable
Physical Connections
©Flegere/Shutterstock Physical connections use a solid medium to connect sending and receiving devices.
These connections include twisted-pair, coaxial, and fiber-optic cables.
Figure 8-5 Fiber-optic cable
• Twisted-pair cable consists of pairs of copper wire that are twisted together. Both
©Hugh Threlfall/Alamy standard telephone lines and Ethernet cables use twisted pair. (See Figure 8-3.)
Ethernet cables are often used in networks and to connect a variety of compo-
nents to the system unit.
• Coaxial cable, a high-frequency transmission cable, replaces the multiple wires of
telephone lines with a single solid-copper core. (See Figure 8-4.) In terms of the
number of telephone connections, a coaxial cable has over 80 times the transmis-
sion capacity of twisted pair. Coaxial cable is used to deliver television signals as
well as to connect computers in a network.
• Fiber-optic cable transmits data as pulses of light through tiny tubes of glass.
(See Figure 8-5.) The data transmission speeds of fiber-optic cables are incred-
ible; recently speeds of 1 petabit per second were measured (a petabit is 1 mil-
lion gigabits). Compared to coaxial cable, it is lighter, faster, and more reliable
at transmitting data. Fiber-optic cable is rapidly replacing twisted-pair cable
telephone lines.
188 chapter 8
Wireless Connections Standard Maximum speed
Wireless connections do not use a solid substance to connect sending and receiving 802.11g 54 Mbps
devices. Rather, they move data through the air. 802.11n 600 Mbps
802.11ac 2.6 Gbps
Most wireless connections use radio waves to communicate. For example, 802.11ax 10.5 Gbps
smartphones and many other Internet-enabled devices use radio waves to place
telephone calls and to connect to the Internet. Primary technologies used for wire-
less connections are Bluetooth, Wi-Fi, microwave, WiMax, cellular, and satellite
connections.
• Bluetooth is a short-range radio communication standard that transmits data over Figure 8-6 Wi-Fi standards
short distances of up to approximately 33 feet. Bluetooth is widely used for wire-
less headsets, printer connections, and handheld devices. Figure 8-7 Microwave dish
• Wi-Fi (wireless fidelity) uses high-frequency radio signals to transmit data. A ©Stuart Gregory/Photodisc/Getty Images
number of standards for Wi-Fi exist, and each can send and receive data at a
different speed. (See Figure 8-6.) Most home and business wireless networks Figure 8-8 GPS navigation
use Wi-Fi.
©Alex Segre/Alamy
• Microwave communication uses high-frequency radio waves. It is sometimes
referred to as line-of-sight communication because microwaves can only
travel in a straight line. Because the waves cannot bend with the curvature of
the earth, they can be transmitted only over relatively short distances. Thus,
microwave is a good medium for sending data between buildings in a city or
on a large college campus. For longer distances, the waves must be relayed
by means of microwave stations with microwave dishes or antennas. (See
Figure 8-7.)
• WiMax (Worldwide Interoperability for Microwave Access) is a new standard
that extends the range of Wi-Fi networks using microwave connections. WiMax
is commonly used by universities and others to extend the capability of existing
Wi-Fi networks.
• Cellular communication uses multiple antennae (cell towers)
to send and receive data within relatively small geographic
regions (cells). Most cell phones and mobile devices use cellular
networks.
• Satellite communication uses satellites orbiting about
22,000 miles above the earth as microwave relay stations.
Many of these are offered by Intelsat, the International Tele-
communications Satellite Consortium, which is owned by
114 governments and forms a worldwide communication system.
Satellites orbit at a precise point and speed above the earth. They
can amplify and relay microwave signals from one transmitter on
the ground to another. Satellites can be used to send and receive
large volumes of data. Uplink is a term relating to sending data
to a satellite. Downlink refers to receiving data from a satel-
lite. The major drawback to satellite communication is that bad
weather can sometimes interrupt the flow of data.
One of the most interesting applications of satellite com-
munications is for global positioning. A network of satellites
owned and managed by the Department of Defense continu-
ously sends location information to earth. Global positioning
system (GPS) devices use that information to uniquely deter-
mine the geographic location of the device. Available in many
automobiles to provide navigational support, these systems are
often mounted into the dash with a monitor to display maps
and speakers to provide spoken directions. Most of today’s
smartphones and tablets use GPS technology for handheld
navigation. (See Figure 8-8.)
Communications and Networks 189
environment Unlike radio waves, infrared uses infrared light waves to communicate over short
distances. Like microwave transmissions, infrared is a line-of-sight communication.
Did you know that GPS Because light waves can only travel in a straight line, sending and receiving devices
technology might help protect must be in clear view of one another without any obstructions blocking that view. One
the environment? Many cars of the most common infrared devices is the TV remote control.
and mobile devices now have
GPS capabilities, and these concept check
tools can help save fuel by
providing drivers with the What are communication channels? List three physical connections.
shortest route to a destination. What is Bluetooth? Wi-Fi? Microwave communication? WiMax?
Most devices now provide What are cellular and satellite communications? GPS? Infrared?
real-time traffic avoidance
data, which will reduce the Connection Devices
carbon emissions and pollution
of cars stuck in traffic. By At one time nearly all computer communication used telephone lines. However, because
finding the best routes and the telephone was originally designed for voice transmission, telephones typically send
avoiding congested areas, and receive analog signals, which are continuous electronic waves. Computers, in con-
you can maximize your fuel trast, send and receive digital signals. (See Figure 8-9.) These represent the presence or
efficiency and help protect the absence of an electronic pulse—the on/off binary signals we mentioned in Chapter 5. To
environment. convert the digital signals to analog signals and vice versa, you need a modem.
Modems
Analog The word modem is short for modulator-demodulator. Modulation is the name of the
process of converting from digital to analog. Demodulation is the process of convert-
Digital ing from analog to digital. The modem enables digital personal computers to commu-
nicate across different media, including telephone wires, cable lines, and radio waves.
Figure 8-9 Analog and digital
signals The speed with which modems transmit data varies. This speed, called transfer rate,
is typically measured in millions of bits (megabits) per second (Mbps). (See F igure 8-10.)
Unit Speed The higher the speed, the faster you can send and receive information. For example, to
Mbps Million bits per second download a complete full-length motion picture (700 MB) on a 1.5-Mbps modem would
Gbps Billion bits per second take about 1 hour. Using a 10.0-Mbps modem would take about 9 minutes.
Tbps Trillion bits per second
There are three commonly used types of modems: DSL, cable, and wireless. (See
Figure 8-10 Typical transfer Figure 8-11.)
rates • A DSL (digital subscriber line) modem uses standard phone lines to create a
high-speed connection directly to your phone company’s offices. These devices
are usually external and connect to the system unit using either a USB or an
Ethernet port.
• A cable modem uses the same coaxial cable as your television. Like a DSL
modem, a cable modem creates high-speed connections using the system unit’s
USB or Ethernet port.
• A wireless modem is also known as a WWAN (wireless wide area network) modem.
Almost all computers today have built-in wireless modems. For those that do not,
wireless adapter cards are available that plug into USB or s pecial card ports.
Connection Service
For years, large corporations have been leasing special high-speed lines from tele-
phone companies. Originally, these were copper lines, known as T1 lines, that could
be combined to form higher-capacity options known as T3 or DS3 lines. These lines
have largely been replaced by faster optical carrier (OC) lines.
Although the special high-speed lines are too costly for most individuals, Inter-
net service providers (as discussed in Chapter 2) do provide affordable connections.
190 chapter 8
DSL Cable Wireless
Figure 8-11 Basic types of modems
(left): ©gilotyna4/Shutterstock; (middle): ©iko/Shutterstock; (right): ©Alex Melnick/Shutterstock
For years, individuals relied on dial-up services using existing telephones and tele-
phone modems to connect to the Internet. This type of service has been replaced
by higher-speed connection services, including DSL, cable, satellite, and cellular
services.
• Digital subscriber line (DSL) service is provided by telephone companies using
existing telephone lines to provide high-speed connections. ADSL (asymmetric
digital subscriber line) is one of the most widely used types of DSL. DSL is much
faster than dial-up.
• Cable service is provided by cable television companies using their existing televi-
sion cables. These connections are usually faster than DSL.
• Fiber-optic service (FiOS) is showing up in some areas, but it is a new technology
and not widely available. Current providers of FiOS include Google and Verizon
with speeds faster than cable or DSL connections.
• Satellite connection services use satellites to provide wireless connections.
Although slower than DSL and cable modem, satellite connections are available
almost anywhere using a satellite-receiving disk.
• Cellular service providers, including Verizon, AT&T, Sprint, and T-Mobile,
support voice and data transmission to wireless devices using cellular networks.
These networks have gone through different generations. First-generation mobile
telecommunications (1G) started in the 1980s using analog radio signals to
provide analog voice transmission service. Second-generation mobile
telecommunications (2G) started in the 1990s using digital radio signals. Third-
generation mobile telecommunications (3G) started in the 2000s and provided
services capable of effective connectivity to the Internet, marking the beginning
of smartphones. Fourth-generation mobile telecommunications (4G) use LTE
(Long Term Evolution) connections to provide faster Internet access, allowing
smartphones to easily stream videos and music. The fifth-generation mobile
telecommunications (5G) is being developed, with speeds that rival home
Internet connections and is expected to be widely available by 2020.
To learn more about how you can use mobile communications, see Making IT Work
for You: The Mobile Office on pages 192 and 193.
Communications and Networks 191
Making IT work for you
THE MOBILE OFFICE
Would you like to turn your daily commute into productive time to finish classwork? When you travel for
business, would you like to be able to take your office with you, wherever you go? Or would you like to
forego traveling all together and telecommute from home? The advances in mobile and high-speed networks
make telecommuting possible from just about anywhere. To become a mobile computing powerhouse, you’ll
need to understand the tools to get online and make the most of the Internet.
• 1 Mobile Hotspot Device
Many cell phone service providers offer stand-
alone devices that connect to a 4G or 5G
network and allow multiple devices near it to
access the Internet via Wi-Fi connection.
• 2 Personal Hotspot Karma, a mobile hotspot device, creates an Internet
connected WiFi network on the go.
Many smartphones can act as mobile hotspot
devices, allowing nearby tablets and laptops Source: Karma Mobility
to connect to the Internet. Sometimes called
tethering, devices can connect to the phone
via Bluetooth, Wi-Fi, or USB cable, and through
that connection access the Internet. Personal
hotspots offer a simple mobile Internet solution
without the additional cost of purchasing a
mobile hotspot device. Unfortunately, using
a personal hotspot will drain your phone’s
battery more quickly, it will increase your
phone’s data plan usage, and it may require
some extra effort to set up. Contact your
cell provider to learn about the costs and
processes associated with setting up a
personal hotspot.
• 3 Public Wi-Fi A personal hotspot allows devices to connect to the
Internet over your phone’s data plan.
Even if you can’t use the Internet on the go—
you can probably get online when you arrive. Source: GottabeMobile
Many public locations, especially airports,
hotels, and coffee shops, offer free or low-cost
Internet connections.
192
Now that you are connected to the Internet, here are some tools that can make your mobile office feel like home:
• 1 Cloud Storage
When on the go, you want your documents to
be available, up to date, and secure. With an
Internet connection, you can connect to cloud
storage services that will hold your important
documents. Through cloud storage, you can
collaborate with co-workers and always be
confident you have the most up-to-date version
of the document. Further, if you lose or damage
your laptop, your documents are stored in
the cloud and will not be lost. Finally, cloud
storage synchs across multiple devices, so you
can review a spreadsheet on your cell phone,
make changes on your laptop, and then share it
with co-workers on your tablet. Popular cloud
services are Google Drive, Microsoft OneDrive,
and Dropbox.
Dropbox is a cloud storage service that works easily with
multiple operating systems.
Source: Dropbox
• 2 Video Conferencing
Video conferencing can allow you to have a
face-to-face meeting without being in the same
room—or even the same country. A camera,
microphone, and speakers will be needed to
video conference—most laptops, tablets, and
cell phones come with these accessories.
Depending on your device, different video
conferencing software is available to you.
Apple has developed FaceTime, Google has
Hangouts, and Microsoft has Skype. FaceTime
is only available between Apple devices, but
Hangouts and Skype can be used on most PCs,
tablets, and cell phones.
The Microsoft videoconfrencing tool, Skype, is a popular
way to communicate with friends, family, and co-workers.
Source: Skype
193
concept check
What is the function of a modem? Compare the three types of modems.
What is a connection service? Compare the five high-speed connection services.
Describe the five generations of mobile communications.
Data Transmission
Several factors affect how data is transmitted. These factors include bandwidth and
protocols.
Bandwidth
Bandwidth is a measurement of the width or capacity of the communication chan-
nel. Effectively, it means how much information can move across the communication
channel in a given amount of time. For example, to transmit text documents, a slow
bandwidth would be acceptable. However, to effectively transmit video and audio, a
wider bandwidth is required. There are four categories of bandwidth:
• Voiceband, also known as low bandwidth, is used for standard telephone commu-
nication. Personal computers with telephone modems and dial-up service use this
bandwidth. Although effective for transmitting text documents, it is too slow for
many types of transmission, including high-quality audio and video.
• Medium band is used in special leased lines to connect midrange computers and
mainframes, as well as to transmit data over long distances. This bandwidth is
capable of very-high-speed data transfer.
• Broadband is widely used for DSL, cable, and satellite connections to the Internet.
Several users can simultaneously use a single broadband connection for high-
speed data transfer.
• Baseband is widely used to connect individual computers that are located close to
one another. Like broadband, it is able to support high-speed transmission. Unlike
broadband, however, baseband can only carry a single signal at a time.
Protocols
For data transmission to be successful, sending and receiving devices must follow a set
of communication rules for the exchange of information. These rules for exchanging
data between computers are known as protocols.
As discussed in Chapter 2, https, or hypertext transfer protocol secure, is widely
used to protect the transfer of sensitive information. Another widely used Internet
protocol is TCP/IP (transmission control protocol/Internet protocol). The essen-
tial features of this protocol involve (1) identifying sending and receiving devices
and (2) breaking information into small parts, or packets, for transmission across
the Internet.
• Identification: Every computer on the Internet has a unique numeric address
called an IP address (Internet protocol address). Similar to the way a postal ser-
vice uses addresses to deliver mail, the Internet uses IP addresses to deliver e-mail
and to locate websites. Because these numeric addresses are difficult for people to
remember and use, a system was developed to automatically convert text-based
addresses to numeric IP addresses. This system uses a domain name server (DNS)
that converts text-based addresses to IP addresses. For example, whenever you
194 chapter 8
URL IP Address
www.mhhe.com 65.39.69.50
DNS
Figure 8-12 DNS converts text-based addresses to numeric IP addresses
enter a URL, say www.mhhe.com, a DNS converts this to an IP address before a
connection can be made. (See Figure 8-12.)
• Packetization: Information sent or transmitted across the Internet usually travels
through numerous interconnected networks. Before the message is sent, it is refor-
matted or broken down into small parts called packets. Each packet is then sent
separately over the Internet, possibly traveling different routes to one common des-
tination. At the receiving end, the packets are reassembled into the correct order.
concept check
What is bandwidth? Describe the four categories.
What are protocols? What is the standard protocol for the Internet?
Define TCP/IP, IP address, and packets.
Networks
A computer network is a communication system that connects two or more computers
so that they can exchange information and share resources. Networks can be set up in
different arrangements to suit users’ needs. (See Figure 8-13.)
Terms
There are a number of specialized terms that describe computer networks. These
terms include
• Node—any device that is connected to a network. It could be a computer, printer,
or data storage device.
• Client—a node that requests and uses resources available from other nodes. Typi-
cally, a client is a user’s personal computer.
• Server—a node that shares resources with other nodes. Dedicated servers special-
ize in performing specific tasks. Depending on the specific task, they may be
called an application server, communication server, database server, file server,
printer server, or web server.
Communications and Networks 195
Router
Printer Nodes
Switch Router
Directory server
Servers
Clients Clients
Figure 8-13 Computer network
• Directory server—a specialized server that manages resources, such as user
accounts, for an entire network.
• Host—any computer system connected to a network that provides access to its
resources.
• Router—a node that forwards or routes data packets from one network to their
destination in another network.
• Switch—central node that coordinates the flow of data by sending messages directly
between sender and receiver nodes. A hub previously filled this purpose by send-
ing a received message to all connected nodes, rather than just the intended node.
• Network interface cards (NIC)—as discussed in Chapter 5, these are expansion
cards located within the system unit that connect the computer to a network.
Sometimes referred to as a LAN adapter.
• Network operating systems (NOS)—control and coordinate the activities of all
computers and other devices on a network. These activities include electronic
communication and the sharing of information and resources.
• Network administrator—a computer specialist responsible for efficient network
operations and implementation of new networks.
196 chapter 8
A network may consist only of personal computers, or it may integrate personal
computers or other devices with larger computers. Networks can be controlled by all
nodes working together equally or by specialized nodes coordinating and supplying
all resources. Networks may be simple or complex, self-contained, or dispersed over a
large geographic area.
concept check
What is a computer network? What are nodes, clients, servers, directory servers,
hosts, routers, and switches?
What is the function of an NIC and an NOS?
What is a network administrator?
Network Types
Clearly, different types of channels—wired or wireless—allow different kinds of net-
works to be formed. Telephone lines, for instance, may connect communications
equipment within the same building or within a home. Networks also may be citywide
and even international, using both cable and wireless connections. Local area, metro-
politan area, and wide area networks are distinguished by the size of the geographic
area they serve.
Local Area Networks
Networks with nodes that are in close physical proximity—within the same building,
for instance—are called local area networks (LANs). Typically, LANs span distances
less than a mile and are owned and operated by individual organizations. LANs are
widely used by colleges, universities, and other types of organizations to link per-
sonal computers and to share printers and other resources. For a simple LAN, see
Figure 8-14.
The LAN represented in Figure 8-14 is a typical arrangement and provides two
benefits: economy and flexibility. People can share costly equipment. For instance, the
four personal computers share the high-speed laser printer and the file server, which
are expensive pieces of hardware. Other equipment or nodes also may be added to the
LAN—for instance, more personal computers, a mainframe computer, or optical disc
storage devices. Additionally, the network gateway is a device that allows one LAN
to be linked to other LANs or to larger networks. For example, the LAN of one office
group may be connected to the LAN of another office group.
There are a variety of different standards or ways in which nodes can be connected
to one another and ways in which their communications are controlled in a LAN. The
most common standard is known as Ethernet. LANs using this standard are some-
times referred to as Ethernet LANs.
Home Networks
Although LANs have been widely used within organizations for years, they are now
being commonly used by individuals in their homes and apartments. These LANs,
called home networks, allow different computers to share resources, including a com-
mon Internet connection. Computers can be connected in a variety of ways, including
electrical wiring, telephone wiring, and special cables. One of the simplest ways, how-
ever, is without cables, or wireless.
Communications and Networks 197
Personal computer Personal computer
High-speed laser printer File server Network
gateway
Personal computer Personal computer
Figure 8-14 Local area network
Figure 8-15 Wireless adapter Wireless LAN
A wireless local area network is typically referred to as a
©Ilya Starikov/Alamy wireless LAN (WLAN). It uses radio frequencies to con-
nect computers and other devices. All communications pass
through the network’s centrally located wireless access point
or base station. This access point interprets incoming radio fre-
quencies and routes communications to the appropriate devices.
Wireless access points that provide Internet access are widely available
in public places such as coffee shops, libraries, bookstores, colleges, and uni-
versities. These access points are known as hotspots and typically use Wi-Fi tech-
nology. Many of these services are free and easy to find using free locator sites such as
www.hotspot-locations.com. Most mobile computing devices have an internal wireless
network card to connect to hotspots. If your mobile device does not have an internal
wireless network card, you can use an external wireless adapter (see Figure 8-15) that
plugs into your computer’s USB port or PC card slot.
Personal Area Network
A personal area network (PAN) is a type of wireless network that works within a very
small area—your immediate surroundings. PANs connect cell phones to headsets, key-
boards to cell phones, and so on. These networks make it possible for wireless devices
to interact with each other. The most popular PAN technology is Bluetooth, with a
maximum range of around 33 feet. Virtually all wireless peripheral devices available
today use Bluetooth, including the controllers on popular game systems like the Play-
Station and Wii.
Metropolitan Area Networks
Metropolitan area networks (MANs) span distances up to 100 miles. These net-
works are frequently used as links between office buildings that are located
throughout a city.
198 chapter 8
Type Description Figure 8-16 Types of networks
LAN Local area network; located within close proximity
Home Local area network for home and apartment use; typically wireless
WLAN Wireless local area network; all communication passes through access point
PAN Personal area network; connects digital devices, such as PDAs
MAN Metropolitan area network; typically spans cities with coverage up to 100 miles
WAN Wide area network for countrywide or worldwide coverage
Unlike a LAN, a MAN is typically not Do you use your laptop to connect to wireless networks at tips
owned by a single organization. Rather, school or in public places such as coffee shops, airports, or
it is owned either by a group of organi- hotels? If so, it is important to use caution to protect your computer and your
zations or by a single network service privacy. Here are a few suggestions:
provider that provides network services
for a fee. 1 Use a firewall. A personal firewall is essential when connecting your computer
Wide Area Networks
directly to public networks. Some firewalls, such as the one built into Windows
8 and Windows 10, will ask whether a new network should be treated as home,
work, or a public network.
Wide area networks (WANs) are coun- 2 Avoid fake hotspots. Thieves are known to set up rogue (or fake) hotspots
trywide and worldwide networks. These
networks provide access to regional in popular areas where users expect free Wi-Fi, such as coffee shops and
service (MAN) providers and typically airports. Because many operating systems automatically connect to the
span distances greater than 100 miles. access point with the strongest signal, you could be connecting to the one set
They use microwave relays and satellites up by the thief. Always confirm that you are connecting to the access point of
to reach users over long distances—for that establishment. Ask an employee if you are unsure.
example, from Los Angeles to Paris. Of
course, the widest of all WANs is the 3 Turn off file sharing. Turning off file-sharing features in your operating system
Internet, which spans the entire globe.
will ensure that no one can access or modify your files.
The primary difference between a
4 Check if connection is encrypted. If the hotspot you are using is protected
with a password, then it is likely encrypted. If it is not, then be very careful with
websites you visit and the information you provide.
PAN, LAN, MAN, and WAN is the geo-
graphic range. Each may have various
combinations of hardware, such as personal computers, midrange computers, main-
frames, and various peripheral devices.
For a summary of network types, see Figure 8-16.
concept check
What is a LAN? Network gateway? Ethernet? Home network?
What is a wireless network? Wireless access point? Hotspot?
What is a PAN? MAN? WAN?
Network Architecture
Network architecture describes how a network is arranged and how resources are
coordinated and shared. It encompasses a variety of different network specifics,
including network topologies and strategies. Network topology describes the physi-
cal arrangement of the network. Network strategies define how information and
resources are shared.
Communications and Networks 199
Figure 8-17 Ring network Switch
Figure 8-19 Tree network Figure 8-18 Star network
Topologies
Figure 8-20 Mesh network A network can be arranged or configured in several differ-
200 chapter 8 ent ways. This arrangement is called the network’s topology.
The most common topologies are
• Bus network—each device is connected to a common
cable called a bus or backbone, and all communications
travel along this bus.
• Ring network—each device is connected to two other
devices, forming a ring. (See Figure 8-17.) When a mes-
sage is sent, it is passed around the ring until it reaches
the intended destination.
• Star network—each device is connected directly to a cen-
tral network switch. (See Figure 8-18.) Whenever a node
sends a message, it is routed to the switch, which then
passes the message along to the intended recipient. The
star network is the most widely used network topology
today. It is applied to a broad range of applications from
small networks in the home to very large networks in
major corporations.
• Tree network—each device is connected to a central
node, either directly or through one or more other
devices. The central node is connected to two or more
subordinate nodes that in turn are connected to other
subordinate nodes, and so forth, forming a treelike
structure. (See Figure 8-19.) This network, also known as
a hierarchical network, is often used to share corporate-
wide data.
• Mesh network—this topology is the newest type and
does not use a specific physical layout (such as a star or a
tree). Rather, the mesh network requires that each node
have more than one connection to the other nodes. (See
Figure 8-20.) The resulting pattern forms the appear-
ance of a mesh. If a path between two nodes is somehow
disrupted, data can be automatically rerouted around
the failure using another path. Wireless technologies are
frequently used to build mesh networks.
Strategies
Every network has a strategy, or way of coordinating the
sharing of information and resources. Two of the most com-
mon network strategies are client/server and peer-to-peer.
Client/server networks use central servers to coordinate
and supply services to other nodes on the network. The Client
server provides access to resources such as web pages, data-
bases, application software, and hardware. (See Figure 8-21.) Server
This strategy is based on specialization. Server nodes coordi- Client
nate and supply specialized services, and client nodes request Client
Figure 8-21 Client/server
the services. Commonly used server operating systems are network
Windows Server, macOS X Server, Linux, and Solaris.
Client/server networks are widely used on the Internet. For example, each time you
open a web browser, your computer (the client) sends out a request for a specific web
page. This request is routed over the Internet to a server. This server locates and sends
the requested material back to your computer.
One advantage of the client/server network strategy is the ability to handle very
large networks efficiently. Another advantage is the availability of powerful network
management software to monitor and control network activities. The major disadvan-
tages are the cost of installation and maintenance.
In a peer-to-peer (P2P) network, nodes have equal authority and can act as both
clients and servers. The most common way to share games, movies, and music over
the Internet is to use a P2P network. For example, special file-sharing software such as
BitTorrent can be used to obtain files located on another personal computer and can
provide files to other personal computers.
P2P networks are rapidly growing in popularity as people continue to share infor-
mation with others around the world. The primary advantage is that they are easy and
inexpensive (often free) to set up and use. One disadvantage of P2P networks is the
lack of security controls or other common management functions. For this reason, few
businesses use this type of network to communicate sensitive information.
concept check
What is a network topology?
Compare bus, ring, star, tree, and mesh topologies.
What is a network strategy?
Compare client/server and peer-to-peer strategies.
Organizational Networks
Computer networks in organizations have evolved over time. Most large organizations
have a complex and wide range of different network configurations, operating sys-
tems, and strategies. These organizations face the challenge of making these networks
work together effectively and securely.
Internet Technologies
Many organizations today employ Internet technologies to support effective commu-
nication within and between organizations using intranets and extranets.
• An intranet is a private network within an organization that resembles the Internet.
Like the public Internet, intranets use browsers, websites, and web pages. Typical
applications include electronic telephone directories, e-mail addresses, employee
Communications and Networks 201
benefit information, internal job openings, and much more. Employees find surfing
their organizational intranets to be as easy and as intuitive as surfing the Internet.
• An extranet is a private network that connects more than one organization. Many
organizations use Internet technologies to allow suppliers and others limited access
to their networks. The purpose is to increase efficiency and reduce costs. For exam-
ple, an automobile manufacturer has hundreds of suppliers for the parts that go into
making a car. By having access to the car production schedules, suppliers can sched-
ule and deliver parts as they are needed at the assembly plants. In this way, opera-
tional efficiency is maintained by both the manufacturer and the suppliers.
Network Security
Large organizations face the challenge of ensuring that only authorized users have
access to network resources, sometimes from multiple geographic locations or across
the Internet. Securing large computer networks requires specialized technology. Three
technologies commonly used to ensure network security are firewalls, intrusion detec-
tion systems, and virtual private networks.
• A firewall consists of hardware and software that control access to a company’s
intranet and other internal networks. Most use software or a special computer called
a proxy server. All communications between the company’s internal networks and
the outside world pass through this server. By evaluating the source and the content
of each communication, the proxy server decides whether it is safe to let a particular
message or file pass into or out of the organization’s network. (See Figure 8-22.)
Organizational Organizational
intranet intranet
Proxy server Extranet Proxy server
connection Firewall
Firewall
Figure 8-22 Intranets, extranets, firewalls, and proxy servers
202 chapter 8
• Intrusion detection systems (IDS) work with firewalls to protect an organiza- privacy
tion’s network. These systems use sophisticated statistical techniques to analyze
all incoming and outgoing network traffic. Using advanced pattern matching In this age of social media and
and heuristics, an IDS can recognize signs of a network attack and disable access smartphones, it can be difficult
before an intruder can do damage. to maintain your privacy on
the Internet—but have you
• Virtual private networks (VPN) create a secure private connection between a considered how to maintain
remote user and an organization’s internal network. Special VPN protocols cre- the privacy of your Internet
ate the equivalent of a dedicated line between a user’s home or laptop computer connection? When traveling it is
and a company server. The connection is heavily encrypted, and, from the per- common to use unfamiliar Wi-Fi
spective of the user, it appears that the workstation is actually located on the connections—at a hotel, airport,
corporate network. or coffee shop—but what
Like organizations, end users have security challenges and concerns. We need confidence do you have that
your Internet activities won’t
to be concerned about the privacy of our personal information. In the next chap- be monitored? Proponents of
ter, we will discuss personal firewalls and other ways to protect personal privacy monitoring point out that public
and security. spaces offer no guarantee of
privacy and a business has the
concept check right to monitor Internet traffic
to deny unsavory web pages.
What are Internet technologies? Compare intranets and extranets. Privacy advocates counter
What is a firewall? What is a proxy server? that many of the most common
What are intrusion detection systems? Internet activities include private
What are virtual private networks? data—such as sharing photos
and receiving e-mails—and
that in offering public Wi-Fi to
perform common Internet tasks,
it is reasonable for a person to
have an expectation of privacy.
What do you think?
Careers in IT
Now that you have learned about computer
Network administrators manage a company’s LAN and WAN networks.
“communications and networks, let me tell you They may be responsible for design, implementation, and maintenance
”about my career as a network administrator. of networks. Duties usually include maintenance of both hardware
and software related to a company’s intranet and Internet networks.
©Amble Design/Shutterstock Network administrators are typically responsible for diagnosing and
repairing problems with these networks. Some network administra-
tors’ duties include planning and implementation of network security
as well.
Employers typically look for candidates with a bachelor’s or an asso-
ciate’s degree in computer science, computer technology, or informa-
tion systems, as well as practical networking experience. Experience
with network security and maintenance is preferred. Also technical
certification may be helpful in obtaining this position. Because network
administrators are involved directly with people in many departments,
good communication skills are essential.
Network administrators can expect to earn an annual salary of
$46,000 to $66,000. Opportunities for advancement typically include
upper-management positions. This position is expected to be among
the fastest-growing jobs in the near future.
Communications and Networks 203
A LOOK TO THE FUTURE
Telepresence Lets You Be There only part of the illusion of being in another place—you
without Actually Being There must also feel and touch the distant objects. Called haptic
technology, specialized gloves and surfaces can give the
Keeping in touch with distant family and friends can be chal- user touch sensations that mimic holding or touching a
lenging. How would you like to feel as if distant loved ones distant object.
were only an arm’s length away? Technology will likely allow
you to not only speak with them, but also feel their touch. Can In the near future, you may visit a doctor’s office with no
you imagine receiving a physical examination from a doctor doctors in it. A high-resolution monitor on the wall lets you
thousands of miles away? All this see a specialist, life size and in perfect detail. The special-
and more could be possible in the
future thanks to an emerging tech- ist puts on virtual reality goggles
nology known as telepresence. and haptic gloves, and a robot in
the room begins to echo her hand
Telepresence seeks to create gestures. As the specialist looks
the illusion that you are actually around the room, dual cameras
at a remote location, seeing, hear- in the robot give her a three-
ing, and, someday maybe, even dimensional view of her patient.
feeling as though you were really The doctor reaches out her hand,
there. It is the natural evolution and the robot arms follow along,
of the telephone call. In the future, taking your arm. The doctor’s
telepresence with likely include force-feedback gloves let her
robots that will allow you to walk hold your arm firmly but comfort-
the halls of your office or other ably, and she can feel your pulse
remote locations from the com- as the robot holds its fingers to
fort of your home. Technology will the inside of your wrist.
continue to evolve to improve our ©Alfa Photo/Shutterstock
lives as we look to the future. In your home, a telepresence
robot might help you with routine
Today’s early implementations, such as Cisco TelePres- chores. A skilled plumber could
ence, use very-high-definition video, acoustically tuned take control of your home telepresence robot to inspect
audio systems, and high-speed networks to create a very pipes and make small repairs. A mechanic can use telepres-
convincing video conferencing experience. However, tele- ence to change your car’s oil or brake pads. You might use
presence could someday go beyond the simple voice and telepresence tools to go onsite to a distant factory floor and
videoconferencing available today, with robotics allowing inspect the manufacturing line without ever leaving your
the telecommuter to change location and pick up objects. office. What do you think—could telepresence technology
The ability to manipulate things through robotic arms is improve enough to convince you that you are somewhere
else, or would the gloves and headset be too distracting?
204
VISUAL SUMMARY Communications and Networks
COMMUNICATIONS COMMUNICATION CHANNELS
©fotoinfot/Shutterstock ©Stuart Gregory/Photodisc/
Getty Images
Communications is the process of sharing data, programs,
and information between two or more computers. Appli- Communication channels carry data from one computer
cations include e-mail, texting, videoconferencing, and to another.
electronic commerce.
Physical Connections
Connectivity Physical connections use a solid medium to connect send-
Connectivity is a concept related to using computer net- ing and receiving devices. Connections include twisted-
works to link people and resources. You can link or con- pair cable (telephone lines and Ethernet cables), coaxial
nect to large computers and the Internet, providing access cable, and fiber-optic cable.
to extensive information resources.
Wireless Connections
The Wireless Revolution Wireless connections do not use a solid substance to con-
Mobile devices like smartphones and tablets have brought nect devices. Most use radio waves.
dramatic changes in connectivity and communications. • Bluetooth—transmits data over short distances; widely
These wireless devices are becoming widely used for com-
puter communication. used for a variety of wireless devices.
Communication Systems • Wi-Fi (wireless fidelity)—uses high-frequency radio
Communication systems transmit data from one location
to another. There are four basic elements: signals; most home and business wireless networks
• Sending and receiving devices originate or accept use Wi-Fi.
messages. • Microwave—line-of-sight communication; used to
• Connection devices act as an interface between send- send data between buildings; longer distances require
microwave stations.
ing and receiving devices and the communication
channel. • WiMax (Worldwide Interoperability for Microwave
• Data transmission specifications are rules and proce- Access)—extends the range of Wi-Fi networks using
microwave connections.
dures for sending and receiving data.
• Cellular—uses cell towers to send and receive data
• Communication channel is the actual connecting or
within relatively small geographic regions or cells.
transmission medium for messages.
• Satellite—uses microwave relay stations; GPS (global
positioning system) tracks geographic locations.
• Infrared—uses light waves over a short distance; line-
of-sight communication.
Communications and Networks 205
To efficiently and effectively use computers, you need to understand the concepts of connectivity, the wireless revolu-
tion, and communication systems. Additionally, you need to know the essential parts of communication technology,
including channels, connection devices, data transmission, networks, network architectures, and network types.
CONNECTION DEVICES NETWORKS
(left): ©gilotyna4/Shutterstock; (middle): ©iko/Shutterstock; Computer networks connect two or more computers.
(right): ©Alex Melnick/Shutterstock Some specialized network terms include
Many communication systems use standard telephone • Node—any device connected to a network.
lines and analog signals. Computers use digital signals. • Client—node requesting resources.
Modems • Server—node providing resources.
Modems modulate and demodulate. Transfer rate is mea- • Directory server—specialized node that manages
sured in megabits per second. Three types are DSL, cable,
and wireless (wireless wide area network, WWAN). resources.
Connection Service
T1, T3 (DS3), and OC (optical carrier) lines provide support • Host—any computer system that provides access to its
for very-high-speed, all-digital transmission for large corpo-
rations. More affordable technologies include dial-up, DSL resources over a network.
(digital subscriber line), ADSL (widely used), cable, fiber-
optic service (FiOS), satellite, and cellular services. 4G • Router—a node that forwards data packets from one
(fourth-generation mobile telecommunications) use LTE
(Long Term Evolution) connections. 5G (fifth-generation network to another network.
mobile telecommunications) are being developed, with
speeds that rival home Internet connections; expected • Switch—node that coordinates direct flow of data
available by 2020.
between other nodes. Hub is an older device that
DATA TRANSMISSION directed flow to all nodes.
Bandwidth measures a communication channel’s width or • NIC (network interface card)—LAN adapter card for
capacity. Four bandwidths are voiceband (low bandwidth),
medium band, broadband (high-capacity transmissions), connecting to a network.
and baseband. Protocols are rules for exchanging data.
Widely used Internet protocols include https and TCP/IP. • NOS (network operating system)—controls and coor-
IP addresses (Internet protocol addresses) are unique
numeric Internet addresses. DNS (domain name server) dinates network operations.
converts text-based addresses to and from numeric IP
addresses. Packets are small parts of messages. • Network administrator—network specialist responsible
for network operations.
NETWORK TYPES
Networks can be citywide or even international, using
both wired and wireless connections.
• Local area networks (LANs) connect nearby devices.
Network gateways connect networks to one another.
Ethernet is a LAN standard. These LANs are called
Ethernet LANs.
• Home networks are LANs used in homes.
• Wireless LANs (WLANs) use a wireless access point
(base station) as a hub. Hotspots provide Internet
access in public places.
• Personal area networks (PANs) are wireless networks
for PDAs, cell phones, and other wireless devices.
• Metropolitan area networks (MANs) link office build-
ings within a city, spanning up to 100 miles.
• Wide area networks (WANs) are the largest type.
They span states and countries or form worldwide net-
works. The Internet is the largest wide area network in
the world.
206 chapter 8
NETWORK ARCHITECTURE ORGANIZATIONAL NETWORKS
Network architecture describes how networks are arranged Internet Technologies
and resources are shared. Internet technologies support effective communication
using intranets and extranets.
Topologies • Intranet—private network within an organization; uses
A network’s topology describes the physical arrangement
of a network. browsers, websites, and web pages. Typical applica-
• Bus network—each device is connected to a common tions include electronic telephone directories, e-mail
addresses, employee benefit information, internal job
cable called a bus or backbone. openings, and much more.
• Ring network—each device is connected to two other • Extranet—like intranet except connects more than one
devices, forming a ring. organization; typically allows suppliers and others lim-
ited access to their networks.
• Star network—each device is connected directly to a
Network Security
central network switch; most common type today. Three technologies commonly used to ensure network
security are firewalls, intrusion detection systems, and
• Tree (hierarchical) network—a central node is con- virtual private networks.
• Firewall—controls access; all communications pass
nected to subordinate nodes forming a treelike
structure. through proxy server.
• Mesh network—newest; each node has two or more • Intrusion detection systems (IDS)—work with fire-
connecting nodes. walls; use sophisticated statistical techniques to recog-
nize and disable network attacks.
Strategies
Every network has a strategy, or way of sharing informa- • Virtual private network (VPN)—creates secure private
tion and resources. Common network strategies include
client/server and peer-to-peer. connection between remote user and organization’s
• Client/server (hierarchical) network—central comput- internal network.
ers coordinate and supply services to other nodes; CAREERS in IT
based on specialization of nodes; widely used on
the Internet; able to handle very large networks Network administrators manage a company’s LAN and
efficiently; powerful network management software WAN networks. Bachelor’s or associate’s degree in com-
available. puter science, computer technology, or information sys-
tems and practical networking experience required.
• Peer-to-peer network—nodes have equal authority and Salary range is $46,000 to $66,000.
act as both clients and servers; widely used to share
games, movies, and music over the Internet; easy to
set up and use; lacks security controls.
Communications and Networks 207
KEY TERMS
1G (first-generation domain name server node (195)
mobile tele- (DNS) (194) optical carrier (OC) (190)
communications) (191) packet (195)
downlink (189) peer-to-peer (P2P)
2G (second-generation DS3 (190)
mobile tele Ethernet (197) network (201)
communications) (191) Ethernet cable (188) personal area network
extranet (202)
3G (third-generation fiber-optic cable (188) (PAN) (198)
mobile tele- fiber-optic service protocol (194)
communications) (191) proxy server (202)
(FiOS) (191) ring network (200)
4G (fourth-generation firewall (202) router (196)
mobile tele- global positioning system satellite (189)
communications) (191) satellite connection
(GPS) (189)
5G (fifth-generation mobile hierarchical service (191)
telecommunications) server (195)
(191) network (200) star network (200)
home network (197) strategy (201)
analog signal (190) host (196) switch (196)
asymmetric digital subscriber hotspot (198) T1 (190)
https (hypertext transfer T3 (190)
line (ADSL) (191) telephone line (188)
backbone (200) protocol secure) (194) topology (200)
bandwidth (194) hub (196) transfer rate (190)
base station (198) infrared (190) transmission control
baseband (194) intranet (201)
Bluetooth (189) intrusion detection system protocol/Internet protocol
broadband (194) (TCP/IP) (194)
bus (200) (IDS) (203) tree network (200)
bus network (200) IP address (Internet protocol twisted-pair cable (188)
cable modem (190) uplink (189)
cable service (191) address) (194) virtual private network
cellular (189) local area network (VPN) (203)
cellular service provider (191) voiceband (194)
cell (189) (LAN) (197) wide area network
cell tower (189) low bandwidth (194) (WAN) (199)
client (195) LTE (Long Term Wi-Fi (wireless
client/server network (201) fidelity) (189)
coaxial cable (188) Evolution) (191) WiMax (Worldwide
communication medium band (194) Interoperability for
megabits per second Microwave
channel (188) Access) (189)
communication system (187) (Mbps) (190) wireless access point (198)
computer network (195) mesh network (200) wireless LAN
connectivity (186) metropolitan area network (WLAN) (198)
demodulation (190) wireless modem (190)
dial-up service (191) (MAN) (198) wireless wide area
digital signal (190) microwave (189) network (WWAN)
digital subscriber line modem (190) modem (190)
modulation (190)
(DSL) (190) network
digital subscriber line (DSL)
administrator (196, 203)
service (191) network architecture (199)
directory server (196) network gateway (197)
network interface card
(NIC) (196)
network operating system
(NOS) (196)
208 chapter 8
MULTIPLE CHOICE
Circle the correct answer.
1. The concept related to using computer networks to link people and resources.
a. connectivity c. TCP/IP
b. GPS d. Wi-Fi
2. A high-frequency transmission cable that delivers television signals as well as connects
computers in a network.
a. coaxial c. 3D
b. hi-def d. twisted pair
3. A short-range radio communication standard that transmits data over short distances of
up to approximately 33 feet.
a. Bluetooth c. DSL
b. broadband d. TCP/IP
4. The speed with which a modem transmits data is called its:
a. digital velocity c. modular rating
b. dynamic rate d. transfer rate
5. The bandwidth typically used for DSL, cable, and satellite connections to the Internet.
a. baseband c. medium band
b. broadband d. voiceband
6. Every computer on the Internet has a unique numeric address called a(n):
a. IP address c. broadcast
b. DNS d. packet
7. Sometimes referred to as a LAN adapter, these expansion cards connect a computer to a
network.
a. PCMCIA c. server
b. NIC d. VPN
8. A device that allows one LAN to be linked to other LANs or to larger networks.
a. IDS c. PAN
b. network gateway d. switch
9. Typically using Wi-Fi technology, these wireless access points are available from public
places such as coffee shops, libraries, bookstores, colleges, and universities.
a. hotspots c. PANs
b. extranets d. LANs
10. Bus, ring, star, tree, and mesh are five types of network:
a. topologies c. strategies
b. protocols d. devices
chapter 8 209
MATCHING
Match each numbered item with the most closely related lettered item. Write your answers in
the spaces provided.
a. analog 1. Type of network topology in which each device is
b. bus connected to a common cable called a backbone.
c. intrusion detection
2. A widely used Internet protocol.
systems 3. Uses high-frequency radio waves.
d. microwave 4. Signals that are continuous electronic waves.
e. network administrator 5. Rules for exchanging data between computers.
f. node 6. Any device that is connected to a network.
g. peer-to-peer 7. A computer specialist responsible for efficient
h. protocols
i. TCP/IP network operations and implementation of new
j. tree networks.
8. This network, also known as a hierarchical network,
is often used to share corporatewide data.
9. In this network, nodes have equal authority and can
act as both clients and servers.
10. Work with firewalls to protect an organization’s
network.
OPEN-ENDED
On a separate sheet of paper, respond to each question or statement.
1. Define communications including connectivity, the wireless revolution, and communi-
cation systems.
2. Discuss communication channels including physical connections and wireless
connections.
3. Discuss connection devices including modems (DSL, cable, and wireless modems) and
connection services (DSL, ADSL, cable, satellite, and cellular connection services).
4. Discuss data transmission including bandwidths (voiceband, medium band, broad-
band, and baseband) as well as protocols (IP addresses, domain name servers, and
packetization).
5. Discuss networks by identifying and defining specialized terms that describe computer
networks.
6. Discuss network types including local area, home, wireless, personal, metropolitan, and
wide area networks.
7. Define network architecture including topologies (bus, ring, star, tree, and mesh) and
strategies (client/server and peer-to-peer).
8. Discuss organization networks including Internet technologies (intranets and extranets)
and network security (firewalls, proxy servers, intrusion detection systems, and virtual
private networks).
210 chapter 8
DISCUSSION
Respond to each of the following questions.
1 Making IT Work for You: THE MOBILE OFFICE
Review the Making IT Work for You: The Mobile Office on pages 192 and 193 and then respond to the
following: (a) What types of professions would get the most out of a mobile office? Why? What type of
office work is best done at work? What office work can be handled while driving? Or on an airplane?
(b) Do you have a mobile Internet device, such as a smartphone or tablet? (If you do not own any,
research a device on the Internet that you feel would be most beneficial to you.) Can your mobile Internet
device be used as a hotspot? Does your service provider allow you to use that feature? (c) Have you ever
connected to a public Wi-Fi? Did you share any private information, including videos, e-mails, credit card
numbers, or passwords, over a public Wi-Fi? How would you protect your data in the future when on a
public Wi-Fi?
2 Privacy: UNAUTHORIZED NETWORK INTRUSION
Review the privacy box on page 203 and then respond to the following: (a) Does a company offering
public Wi-Fi have the right to monitor the traffic on its own network? Does it have the right to read the
e-mails that are downloaded on that network? Does it have the right to record the passwords that are
sent over that network? Where would you draw the line, and why? (b) Does the government have the
right to monitor the Internet activities of its citizens? What data should the government collect about
its citizens’ Internet use, and how long should the government hold on to that data? Would your opinion
change if you knew terrorists were using the Internet to plan crimes? Would your opinion change if you
knew politicians were using collected data to influence election outcomes?
3 Ethics: ELECTRONIC MONITORING
Review the Ethics box on page 188, and respond to the following: (a) Is it unethical for an organization or
corporation to use programs to monitor communications on its network? Why or why not? (b) Is it unethi-
cal for a government agency (such as the FBI) to monitor communications on the Internet or gather your
records from the websites you visit? Why or why not? (c) Do you feel that new laws are needed to handle
these issues? How would you balance the needs of companies and the government with the needs of
individuals? Explain your answers.
4 Environment: GPS
Review the Environment box on page 190, and then respond to the following: (a) Identify ways in which
GPS could benefit the environment. You need not limit your response to applications in motor vehicles.
(b) Have you used a GPS device or mobile navigation app? If so, describe what you used it for. If not, do
you think that you will in the near future? (c) Do you think that GPS should be standard equipment for
every new car? Why or why not? (d) Do you think that it should be required by law? Why or why not?
Design Elements: Concept Check icons: ©Dizzle52/Getty Images;
Making IT Work for You: ©Shutterstock/cifotart
chapter 8 211
9chapter Privacy, Security,
and Ethics
©Vicente Barcelo Varona/Shutterstock
Why should I read this chapter?
©Franck Boston/Shutterstock In today’s digital world, your every action is recorded, analyzed, and
sold. Your Internet service provider sells your browsing history to
your employer, your grocery store sells your eating habits to your
health insurer, and your credit card company sells your shopping
habits to advertisers. With this information, your employer decides
to pass you over for a promotion, your insurer decides to increase
your insurance rates, and advertisers use your data to find the
moment when you are most vulnerable to advertising.
What rights do you have to your information? What laws pro-
tect you? This chapter covers the things you need to know to be
prepared for this ever-changing world, including:
• Cybercrime—protect yourself from viruses, Internet scams,
and identity theft.
• Privacy rights—learn what companies can legally record about
your Internet usage and how they use that information.
• Safe computing—avoid embarrassment and worse by knowing the
way Facebook and social networking sites share your information.
Learning Objectives
After you have read this chapter, you should be able to:
1 Describe the impact of large databases, private networks, the Internet, and the web on
privacy.
2 Discuss online identity and the major laws on privacy.
3 Discuss cybercrimes, including identity theft, Internet scams, data manipulation, ransomware, and
denial of service.
4 Describe social engineering and malicious software, including crackers, malware, viruses, worms,
and Trojan horses.
5 Discuss malicious hardware, including zombies, botnets, rogue Wi-Fi networks, and infected USB
flash drives.
6 Detail ways to protect computer security, including restricting access, encrypting data, anticipat-
ing disasters, and preventing data loss.
7 Discuss computer ethics, including copyright law, software piracy, digital rights management, the
Digital Millennium Copyright Act, as well as cyberbullying, plagiarism, and ways to identify plagiarism.
213
Introduction There are more than 1 billion personal computers in use today. What are
the consequences of the widespread presence of this technology? Does
“Hi, I’m Ann, and I’m an IT security analyst. I’d technology make it easy for others to invade our personal privacy? When
like to talk with you about privacy, security, we apply for a loan or for a driver’s license, or when we check out at the
and ethics, three critical topics for anyone supermarket, is that information about us being distributed and used with-
who uses computers today. I would also like to out our permission? When we use the web, is information about us being
talk about how you can protect your privacy, collected and shared with others? How can criminals use this information
”ensure your security, and act ethically. for ransom, blackmail, or vandalism?
This technology prompts lots of questions—very important questions.
Perhaps these are some of the most important questions for the 21st cen-
tury. To efficiently and effectively use computers, you need to be aware of
the potential impact of technology on people and how to protect yourself
on the web. You need to be sensitive to and knowledgeable about personal
privacy and organizational security.
©loveguli/E+/Getty Images
People
As we have discussed, information systems consist of people, procedures, software,
hardware, data, and the Internet. This chapter focuses on people. Although most
everyone agrees that technology has had a very positive impact on people, it is impor-
tant to recognize the negative, or potentially negative, impacts as well.
Effective implementation of computer technology involves maximizing its positive
effects while minimizing its negative effects. The most significant concerns are
• Privacy: What are the threats to personal privacy, and how can we protect
ourselves?
• Security: How can access to sensitive information be controlled, and how can we
secure hardware and software?
• Ethics: How do the actions of individual users and companies affect society?
Let us begin by examining privacy.
Privacy
Technology makes it possible to collect and use data of all kinds, including informa-
tion about people. The websites you visit, the stores where you shop, and the tele-
phone calls you make are all examples of information about you. How would you feel
if you learned such information was being collected or shared? Would it matter who
was collecting it, or how it was being used, or whether it was even correct?
214 chapter 9
Privacy concerns the collection and use of data about individuals. There are three privacy
primary privacy issues:
• Accuracy relates to the responsibility of those who collect data to ensure that the An unmanned aerial vehicle
(UAV or drone) is an aircraft
data is correct. without a human pilot. The U.S.
• Property relates to who owns data. military uses drones to take
• Access relates to the responsibility of those who have data to control who is able photographs, record videos, and
run bombing missions without
to use that data. risk to American pilots. Drones
are also used domestically to
Large Databases patrol the U.S. borders and to
Large organizations are constantly compiling information about us. The federal gov- observe private locations in
ernment alone has over 2,000 databases. Every day, data is gathered about us and search of drugs. Opponents
stored in large databases. For example, telephone companies compile lists of the calls of drones say that they violate
we make, the numbers called, locations from GPS-enabled smartphones, and so on. personal privacy rights;
Credit card companies maintain user databases that track cardholder purchases, proponents of drones say that
payments, and credit records. Supermarket scanners in grocery checkout counters as long as the drone is in public
record what we buy, when we buy it, how much we buy, and the price. Financial air space, it does not violate
institutions, including banks and credit unions, record how much money we have, personal privacy rights. What
what we use it for, and how much we owe. Search engines record the search histories do you think? If a drone were to
of their users, including search topics and sites visited. Social networking sites collect observe your backyard, would it
every entry. be violating your privacy rights?
What if a drone observed
Effectively, every digital event—whether using a telephone or smartphone, buying and/or took photographs
a product or service, or sending or receiving any electronic communication—is col- through the windows in your
lected and recorded. As a result, the size and the number of databases are explod- home? Do drones have the right
ing. In fact, it is widely reported that 90 percent of all of today’s digitally stored data to track you when you go to
was collected in just the last two years. This ever-growing volume of data is often public places? Should drones be
referred to as big data. used to follow and photograph
individuals in public places?
A vast industry of data gatherers known as information resellers or information
brokers now exists that collects, analyzes, and sells such personal data. (See F igure 9-1.)
Using publicly available databases and in many cases nonpublic databases, informa-
tion resellers create electronic profiles, or highly detailed and personalized descrip-
tions of individuals.
Figure 9-1 Information
reseller’s website
Source: Spokeo
Privacy, Security, and Ethics 215
Figure 9-2 Google Street
View
Source: Google and the Google logo
are registered trademarks of Google
Inc.
Almost certainly, you have an electronic profile that includes your name, address,
telephone number, Social Security number, driver’s license number, bank account num-
bers, credit card numbers, telephone records, shopping and purchasing patterns, and
more. Information resellers sell these electronic profiles to direct marketers, fund-r aisers,
and others. Many provide these services on the web for free or for a nominal cost.
These profiles can reveal more than you might wish to make public and have an
impact beyond what you might imagine. This raises many important issues, including
• Collecting public, but personally identifying, information: What if people
a nywhere in the world could view detailed images of you, your home, or your
vehicle? Using detailed images captured with a specially equipped van, Google’s
Street View project allows just that. Street View makes it possible to take a vir-
tual tour of many cities and neighborhoods from any computer with a connec-
tion to the Internet. (See Figure 9-2.) Although the images available on Street
View are all taken in public locations, some have objected to the project as being
an intrusion on their privacy.
As digital cameras and webcams become cheaper and software becomes more
sophisticated, it is likely that many more issues involving personal privacy in pub-
lic spaces will need to be addressed. Such a combination of computing technolo-
gies could, for example, make real-time tracking of individuals in public places
possible.
• Spreading information without personal consent: How would you feel if an
employer were using your Facebook, Twitter, or other social networking profiles
to make decisions about hiring, placement, promotion, and firing? It is a common
practice today for many organizations.
As we have discussed in Chapter 2, social networking is designed for open shar-
ing of information among individuals who share a common interest. Unfortunately,
this openness can put individuals using social networking sites at risk. In fact,
some have lost their jobs after posting unflattering remarks about their supervisor
or after discussing their dislike of their current job. Deeper analysis of your social
networking profile may reveal even more about yourself than you intend.
216 chapter 9
The potential to inadvertently share personal information extends past what privacy
you might post to your social networking site. As an example, without your knowl-
edge or permission, a social networking friend might tag or identify you in a photo Sharing personal information
on his or her site. Once tagged, that photo can become part of your electronic pro- on a social networking site like
file and available to others without your consent. Facebook is a voluntary activity.
• Spreading inaccurate information: How would you like to be turned down for However, many individuals
a home loan because of an error in your credit history? This is much more com- do not fully understand the
mon than you might expect. What if you could not find a job or were fired from complex sharing and privacy
a job because of an error giving you a serious criminal history? This can and has policies of these networks.
happened due to simple clerical errors. In one case, an arresting officer while This often causes unintentional
completing an arrest warrant incorrectly recorded the Social Security number sharing with people outside
of a criminal. From that time forward, this arrest and the subsequent conviction their intended social circle. The
became part of another person’s electronic profile. This is an example of mistaken social networks themselves
identity in which the electronic profile of one person is switched with another. have come under fire from
privacy groups, who say
It’s important to know that you have some recourse. The law allows you to gain that these companies use
access to those records about you that are held by credit bureaus. Under the complex settings and policies
Freedom of Information Act, you are also entitled to look at your records held by to get users to share more
government agencies. (Portions may be deleted for national security reasons.) information than intended. This
information is in turn shared
Private Networks with advertisers. Do you think
Suppose you use your company’s electronic mail system to send a co-worker an unflat- social networking companies
tering message about your supervisor or to send a highly personal message to a friend. are a threat to privacy?
Later you find the boss has been reading these e-mails. In fact, many businesses search
employees’ electronic mail and computer files using employee-monitoring software.
These programs record virtually everything you do on your computer. One proposed
law would not prohibit this type of electronic monitoring, but would require employ-
ers to provide prior written notice. Employers also would have to alert employees dur-
ing the monitoring with some sort of audible or visual signal. If you are employed and
would like to know your company’s current policy on monitoring electronic communi-
cation, contact your human relations department.
concept check
Describe how large databases can effect our privacy.
What is big data? Information resellers? Electronic profiles?
List three important issues related to electronic profiles. What is mistaken identity?
What is the Freedom of Information Act?
What are private networks? What is employee-monitoring software? Is it legal?
The Internet and the Web
When you send e-mail on the Internet or browse the web, do you have any concerns
about privacy? Most people do not. They think that as long as they are using their
own computer and are selective about disclosing their names or other personal infor-
mation, then little can be done to invade their personal privacy. Experts call this the
illusion of anonymity that the Internet brings.
As we discussed in Chapter 8, every computer on the Internet is identified by a
unique number known as an IP address. IP addresses can be used to trace Internet
activities to their origin, allowing computer security experts and law enforcement offi-
cers to investigate computer crimes such as unauthorized access to networks or shar-
ing copyright files without permission.
Privacy, Security, and Ethics 217
• 1 In the top-right corner of the browser When you browse the web, your browser stores critical infor-
window, select the Chrome Menu button. mation onto your hard disk, typically without you being aware of
it. This information, which contains records about your Internet
activities, includes history and temporary Internet files.
• H istory files include the locations, or addresses, of sites that
you have recently visited. This history file can be displayed
by your browser in various locations, including the address
bar (as you type) and the History page. To view your browsing
history using Google Chrome, follow the steps in Figure 9-3.
• Temporary Internet files, also known as the browser cache,
contain web page content and instructions for displaying
this content. Whenever you visit a website, these files are
saved by your browser. If you leave a site and then return
later, these files are used to quickly redisplay web content.
• 2 Select History. Another way your web activity can be monitored is with
cookies. Cookies are small data files that are deposited on
your hard disk from websites you have visited. Based on your
browser’s settings, these cookies can be accepted or blocked. To
see how to block cookies using Google Chrome, see Figure 9-4.
Although you will generally not be aware when a website gener-
ates a cookie, the personalized experiences you enjoy on the web
are often a result of those cookies. Although cookies are harmless
in and of themselves, what makes them a potential privacy risk is
that they can store information about you, your preferences, and
your browsing habits. The information stored generally depends
on whether the cookie is a first-party or a third-party cookie.
Figure 9-3 Viewing history • A first-party cookie is one that is generated (and then read)
files only by the website you are currently visiting. Many web-
sites use first-party cookies to store information about the
Source: Google and the Google logo current session, your general preferences, and your activity
are registered trademarks of Google on the site. The intention of these cookies is to provide a
Inc. personalized experience on a particular site. For example,
when you revisit a particular electronic commerce site, a
previously deposited cookie can provide information so that
you can be greeted by name and presented with sales and
promotions that interest you.
• A third-party cookie is usually generated by an advertising company that is affiliated
with the website you are currently visiting. These cookies are used by the advertising
company to keep track of your web activity as you move from one site to the next.
For this reason, they are often referred to as tracking cookies. Critics of this prac-
tice claim that your privacy is being violated because your activity is being recorded
across multiple websites. Defenders of this practice argue that these cookies are
beneficial because they help websites deliver ads that interest you. For example, sup-
pose you visit four different websites that employ the same advertising agency. The
first three sites are about cars, but the fourth is a search engine. When you visit the
fourth site, you will likely see a car advertisement because your cookie showed that
you had been visiting car-related websites.
Some users are not comfortable with the idea of web browsers storing so much
information in the form of temporary Internet files, cookies, and history. For this rea-
son, browsers now offer users an easy way to delete their browsing history. To see how
to delete browsing histories using Google Chrome, see Figure 9-5. In addition, most
browsers also offer a privacy mode, which ensures that your browsing activity is not
recorded on your hard disk. For example, Google Chrome provides Incognito Mode
accessible from the Chrome menu, and Safari provides Private Browsing accessible
from the Safari option on the main menu.
218 chapter 9
• 1 Select the Chrome Menu button. • 1 Select the Chrome Menu button.
• Choose Settings, then click Show advanced • Choose Settings and then click Show
settings. advanced settings.
• 2 Select the Content Settings button in the • Select the Content Settings button in the
Privacy section. Privacy section.
• Click the check box next to “Block third-party • 2 Select check boxes for items
cookies and site data.” to be deleted.
• Click Done. • Choose the Clear browsing data button.
Figure 9-4 Blocking cookies Figure 9-5 Deleting browsing history
Source: Google and the Google logo are registered trademarks Source: Google and the Google logo are registered trademarks of
of Google Inc. Google Inc.
Although these web browser files can concern many individuals, several other
threats could potentially violate your privacy. Web bugs, which are invisible images
or HTML code hidden within a web page or e-mail message, can be used to transmit
information without your knowledge. When a user opens an e-mail containing a web
bug, information is sent back to the source of the bug. The receiving server will now
know that this e-mail address is active. One of the most common web bugs is used by
companies that sell active mailing lists to spammers. Because of this deception, many
e-mail programs now block images and HTML code from unknown senders. It is up
to the user to decide whether or not to allow such content to be displayed for current
and future messages.
The most dangerous type of privacy threat comes in the form of spyware. The term
spyware is used to describe a wide range of programs that are designed to secretly record
and report an individual’s activities on the Internet. Some of these programs can even
make changes to your browser in order to deceive you and manipulate what you see
online. Computer monitoring software is perhaps the most invasive and dangerous type
Privacy, Security, and Ethics 219
Figure 9-6 Antispyware
Source: Norton
ethics of spyware. One type of computer monitoring software, known as a keylogger, records
every activity and keystroke made on your computer system, including credit card num-
bers, passwords, and e-mail messages. Computer monitoring software can be deposited
onto your hard drive without your knowledge by a malicious website or by someone
Data encryption protects your installing the program directly onto your computer. Although such software is deadly in
bank accounts and private the hands of criminals, it can be legally used by companies monitoring employees or law
e-mails, but it also allows enforcement officials who are collecting evidence.
criminals to hide evidence
from police. Some government Unfortunately, many spyware programs go undetected, largely because users have
agencies want to limit the power no idea they are infected. Spyware will run in the background, invisible to the aver-
of data encryption to make it age user. Other times, it disguises itself as useful software, such as a security pro-
easier to find and jail criminals. gram. Various studies have demonstrated that an alarming number of computers are
Privacy advocates argue infected with spyware. The financial impact to individuals, companies, and financial
that limiting encryption gives institutions is estimated at billions of dollars.
criminals and dictators tools that
will be used to steal data and One of the best defenses against spyware is to exercise caution when visiting new
suppress freedoms. Security websites and downloading software from an unknown source. Another defense
advocates respond that to involves using a category of software known as antispyware or spy removal programs,
which are designed to detect and remove various types of privacy threats. (See
protect citizens from criminals, F igure 9-6.) For a list of some of these programs, see Figure 9-7.
the police must be able to
search encrypted devices when
warranted. Should governments Online Identity
be given a skeleton key to bypass
encryption? Should unbreakable Another aspect of Internet privacy comes from online identity, the information that
encryption be illegal? people voluntarily post about themselves online. With the popularity of social net-
working, blogging, and photo- and video-sharing sites, many people post intimate
details of their lives without considering the consequences. Although it is easy to
think of online identity as something shared between friends, the archiving
and search features of the web make it available indefinitely to anyone who
Program Website cares to look.
Ad-Aware www.adaware.com There are any number of cases of people who have lost their jobs on
the basis of posts on social networking sites. These job losses range from a
Norton Security www.norton.com teacher (using off-color language and photos showing drinking) to a chief
Windows Defender www.microsoft.com financial officer of a major corporation (discussing corporate dealings and
financial data). The cases include college graduates being refused a job
because of Facebook posts. How would you feel if information you posted
Figure 9-7 Antispyware programs about yourself on the web kept you from getting a job?
220 chapter 9
Major Laws on Privacy
Some federal laws governing privacy matters have been created. For example, the
Gramm-Leach-Bliley Act protects personal financial information, the Health Insurance
Portability and Accountability Act (HIPAA) protects medical records, and the Family
Educational Rights and Privacy Act (FERPA) restricts disclosure of educational records.
Most of the information collected by private organizations is not covered by exist-
ing laws. However, as more and more individuals become concerned about controlling
who has the right to personal information and how that information is used, compa-
nies and lawmakers will respond.
concept check
What is the illusion of anonymity? Define and compare history files and temporary
Internet files. What is Privacy mode?
What is a cookie? A first-party cookie? A third-party cookie?
What is a web bug? Spyware? Keylogger? Antispyware? Online identity?
Describe three federal laws to protect privacy.
Security
We are all concerned with having a safe and secure environment to live in. We are
careful to lock our car doors and our homes. We are careful about where we walk at
night and whom we talk to. This is personal security. What about computer security?
What if someone gains unauthorized access to our computer or other computers that
contain information about us? These people are commonly known as computer hack-
ers. It should be noted that not all hackers are intent on malicious actions and that not
all are criminals.
Security involves protecting individuals and organizations from theft and danger.
Computer security specifically focuses on protecting information, hardware, and soft-
ware from unauthorized use, as well as preventing or limiting the damage from intru-
sions, sabotage, and natural disasters.
Cybercrime Identity theft is a growing problem, and can be financially devas- tips
Cybercrime or computer crime is any tating if you are a victim. Thieves are after anything that can help
criminal offense that involves a com- them steal your identity, from your Social Security number and date of birth to
puter and a network. It was recently account information and passwords. Here are some steps to help protect your
estimated that cybercrime affects over identity:
400 million people and costs over $400
billion each year. Cybercrimes can take 1 Be careful what you write on the Internet. Never post personal information on
various forms, including identity theft,
Internet scams, data manipulation, ran- forums or social networking areas that are public or in response to an e-mail
somware, and denial of service attacks. from someone you do not know or trust.
• Identity theft is the illegal assump- 2 Only do business on the Internet with companies you know to be legitimate.
tion of someone’s identity for the
purposes of economic gain. Stolen 3 When selling a computer, be sure to completely remove all personal information
identities are used to steal credit
cards and mail and to commit other from the hard drive. To ensure that your personal information is erased,
crimes. It is estimated that identity consider using a free erasure software tool, such as Dban (www.dban.com).
thieves stole $16 billion and victim-
ized 15.4 million individuals. 4 Monitor your credit. Each year, you are entitled to a free personal credit report
from each of the three major credit reporting agencies. Monitor your credit by
requesting a report every four months from a different reporting agency. The
official site for this service is www.annualcreditreport.com.
Privacy, Security, and Ethics 221
Type Descriptions • I nternet scams are scams using the
Advance Guaranteed low-rate loans available to almost anyone. After the Internet. Internet scams have created
fee loans applicant provides personal loan-related information, the loan is financial and legal problems for many
granted subject to payment of an “insurance fee.” thousands of people. Almost all the
Auction Merchandise is selected and payment is sent. Merchandise is never scams are initiated by a mass mailing
fraud delivered. to unsuspecting individuals. Recently,
Fake A website or e-mail warns you that you are at risk of being infected Interpol busted a criminal network of
anitvirus by a computer virus and you need to download and install the security 40 people across Nigeria, Malaysia,
software software they recommend. Ironically, the security software is fake and and South Africa accused of using
will install malicious software on your computer. Internet scams to steal more than $60
Nigerian A classic e-mail scam. The recipient receives an e-mail from a wealthy million. See Figure 9-8 for a list of
Scam foreigner in distress who needs your bank account information to common types of Internet scams.
safely store their wealth, and for your troubles you will receive a large
amount of money. Of course, once the scammer has your bank account • Data manipulation is the unau-
information, your accounts will be drained and they will disappear. thorized access of a computer
network and copying files to or
Figure 9-8 Common Internet scams from the server. This can be as sim-
ple as making a post in Facebook
when logged in as some-
one else or as complex as feeding
a company false reports to change their business practices. Unlike other cyber-
crimes, data manipulation can occur for months, even years, without the victims
being aware of the security breach, making it hard to detect.
• Ransomware is malicious software that encrypts your computer’s data and ran-
soms the password to the user. In 2017, the ransomware “WannaCry” infected
over 250,000 computers in over 150 countries. The WannaCry ransomware attack
infected all types of businesses, halting production at car manufacturing plants
and delaying patient treatment at hospitals.
• Denial of service A denial of service (DoS) attack attempts to slow down or stop
a computer system or network by flooding a computer or network with requests
for information and data. These requests can come from a single computer issuing
repeated requests. Widely used today is a variation known as distributed denial
of service (DDoS), which coordinates several computers
making repeated requests for service. The targets of these
Type Descriptions attacks are usually Internet service providers (ISPs) and
Identity theft Illegal assumption of someone’s identity for specific websites. Once under attack, the servers at the ISP
economic gain or the website become overwhelmed with these requests
Internet scam Scams over the Internet usually initiated by for service and are unable to respond to legitimate users.
mass e-mail As a result, the ISP or website is effectively shut down.
Data manipulation Unauthorized access to a computer network
and copying of files With cybercrime on the rise and the high-profile vic-
Ransomware Encrypts data on a user’s computer and then tims of cybercrime in the news, it is important to under-
ransoms password to access encrypted data stand the tools the cybercriminal uses to harm his victims.
Denial of service Slows down or stops a computer system or Knowledge of these tools will help you make smarter
(DoS) network by flooding it with repeated requests choices and protect yourself from becoming a victim. The
for information and/or data tools of the cybercriminal include social engineering, mali-
Figure 9-9 Common cybercrimes cious software, and malicious hardware. For a summary of
cybercrimes, see Figure 9-9.
concept check
What is cybercrime?
What are identity theft and Internet scams?
What are data manipulation, ransomware, and denial of service attacks?
222 chapter 9
Social Engineering privacy
Often the least secure parts of a network or computer are the humans who work with
it. Social engineering is the practice of manipulating people to divulge private data. Did you know that the World
For example, a criminal may call you at work, pretending to be an IT worker who Wide Web contains websites
needs your password and user name, or they may “friend” you on social media to purposely hidden from you?
get access to private information. Social engineering has played a key role in iden- Some websites are designed
tity theft, Internet scams, and data manipulation. One of the most common social to be hidden from standard
engineering techniques is phishing (pronounced “fishing”). Phishing attempts to trick search engines and allow
Internet users into thinking a fake but official-looking website or e-mail is legitimate. people to communicate in a
Phishing has grown in sophistication, replicating entire websites, like PayPal, to try to secure and anonymous manner.
lure users into divulging their financial information. These hidden websites make
up the Dark Web and require
Malicious Software special software that makes it
A cracker is a computer criminal who creates and distributes malicious programs or nearly impossible to identify
malware, which is short for malicious software. Malware is specifically designed to who is using it. The ability to
damage or disrupt a computer system. The three most common types of malware are communicate anonymously
viruses, worms, and Trojan horses. attracts criminals who want
to sell drugs, share child
• Viruses are programs that migrate through networks and operating systems, and pornography, or profit from
mostly attach themselves to other programs and databases. Although some viruses the poaching of endangered
are relatively harmless, many can be quite destructive. Once activated, these animals. This same anonymity
destructive viruses can alter and/or delete files. allows people in countries
where political dissent is
• Worms are programs that simply replicate themselves over and over again. Once dangerous and free speech is
active in a network, the self-replicating activity clogs computers and networks censored to communicate, plan,
until their operations are slowed or stopped. Unlike a virus, a worm typically does and organize toward a more
not attach itself to a program or alter and/or delete files. Worms, however, can free and open society without
carry a virus. Once a virus has been deposited by a worm onto an unsuspecting fear of jail or execution. Prior
computer system, the virus will either activate immediately or lie dormant until to reading this Privacy section,
some future time. were you aware of the Dark
Web? Do you think it should be
• Trojan horses are programs that appear to be harmless; however, they contain stopped? Do you think it should
malicious programs. Trojan horses are not viruses. Like worms, however, they be regulated?
can be carriers of viruses. The most common types of Trojan horses appear as
free computer games and free antivirus software that can be downloaded from
the Internet. When a user installs one of these programs, the Trojan horse also
secretly installs a virus on the computer system. The virus then begins its mischief.
Some of the most common Trojan horses claim to provide free antivirus programs.
When a user downloads one of these programs, the Trojan horse first installs
a virus that locates and disables any existing virus protection programs before
depositing other viruses.
Malicious Hardware
Criminals use computer hardware to steal information, infect computers with mali-
cious software, and disrupt computer systems. The most common malicious hardware
includes zombie botnets, rogue Wi-Fi hotspots, and infected USB flash drives.
• Zombies are computers infected by a virus, worm, or Trojan horse that allows
them to be remotely controlled for malicious purposes. A collection of zombie
computers is known as a botnet, or robot network. Botnets harness the combined
power of many zombies for malicious activities like password cracking, denial of
service attacks, or sending junk e-mail. Because they are formed by many comput-
ers distributed across the Internet, botnets are hard to shut down even after they
are detected. Unfortunately for individual computer owners, it also can be difficult
to detect when a personal computer has been compromised.
• Rogue Wi-Fi Hotspots—Free Wi-Fi networks are available almost everywhere,
from libraries to fast-food restaurants and coffee shops. Rogue Wi-Fi hotspots imi-
tate these free networks. These rogue networks operate close to the legitimate free
Privacy, Security, and Ethics 223
hotspots and typically provide stronger signals that many users unsuspectingly
connect to. Once connected, the rogue networks capture any and all information
sent by the users to legitimate sites, including user names and passwords.
• Infected USB flash drives—USB drives can hide viruses and other malicious soft-
ware. Crackers will abandon these drives in the hope that others will find them,
plug them into their computer, and become infected. Infected drives have also
been found distributed for free at conferences and slipped into people’s mailboxes.
concept check
What is social engineering? What is phishing?
What is malicious software? A cracker? Viruses? Worms? Trojan horses?
What is malicious hardware? Zombies? Botnets? Rogue Wi-Fi hotspots? Infected
USB flash drives?
Measures to Protect Computer Security
There are numerous ways in which computer systems and data can be compromised
and many ways to ensure computer security. The Computer Fraud and Abuse Act
makes it a crime for unauthorized persons even to view—let alone copy or damage—
data using any computer across state lines. It also prohibits unauthorized use of any
government computer or a computer used by any federally insured financial institu-
tion. Offenders can be sentenced up to 20 years in prison and fined up to $100,000.
However, the best protection for computer security is to be prepared. Some of the
principal measures to ensure computer security are restricting access, encrypting
data, anticipating disasters, and preventing data loss.
Restricting Access Security experts are constantly devising ways to protect com-
puter systems from access by unauthorized persons. Sometimes security is a matter of
putting guards on company computer rooms and checking the identification of every-
one admitted. However, the most common way to restrict access is the use of a pass-
word. Passwords are secret words or phrases (including numbers, letters, and special
characters) that must be keyed into a computer system to gain access. For many applica-
tions on the web, users assign their own passwords.
The strength of a password depends
on how easily it can be guessed. A
tips Security professionals warn that most people use passwords dictionary attack uses software to try
that are too easily guessed. They categorize passwords as thousands of common words sequen-
weak (easily guessed) or strong (difficult to guess). A weak password can tially to gain unauthorized access to a
be guessed in a matter of seconds; a strong one would take years to crack. user’s account. For this reason, words,
Make sure you have a strong password by employing the following tips when names, and simple numeric patterns
creating a password. make weak or poor passwords. Strong
passwords have at least eight characters
1 Use a password with at least eight characters. The fewer the characters, the and use a combination of letters, num-
bers, and symbols.
easier it is to guess.
Newer technology allows access to
2 Do not use your user name, real name, or company name in your password. The be restricted by passwords that do not
require secret words or phrases. Win-
first thing a cracker will try is variations of your personal information.
3 Do not use a complete word. Using a computer, a cracker can easily try every
word in the dictionary as a password guess.
4 Do not reuse passwords. If a user’s password for one account is compromised, dows 10 includes an application, Picture
crackers will attempt to use that password on the user’s other accounts. Password, that accepts a series of ges-
5 Create a password that contains at least one of each of the following tures over a picture of the user’s choice
to gain access. Other times, biometric
characters: uppercase letter, lowercase letter, number, and symbol.
scanning devices such as fingerprint
224 chapter 9
Fingerprint scan Iris scan
Figure 9-10 Biometric scanning devices
Left: ©Anatoliy Babiy/Getty Images; Right: ©Cristian Baitg/Getty Images
and iris (eye) scanners are used to access restricted data. (See Figure 9-10.) Numerous
applications use face recognition to allow access to a computer system. For example,
Microsoft’s Windows 10 and Apple’s iOS 11 include facial recognition software, which
uses specialized cameras to identify users and automatically log them in. There are also
several face recognition apps for mobile devices, including True Key by McAfee and
Intel Security Group.
As mentioned in previous chapters, individuals and organizations use a variety of
ways to perform and automate important security tasks:
• Security suites provide a collection of utility programs designed to protect your
privacy and security while you are on the web. These programs alert users when
certain kinds of viruses and worms enter their system. Two of the most widely
used are Avast! Free Antivirus and Microsoft Windows Defender. Unfortunately,
new viruses are being developed all the time, and not all viruses can be detected.
The best way to stay current is through services that keep track of viruses on a
daily basis. For example, Symantec, McAfee, and Microsoft all track the most seri-
ous virus threats. (See Figure 9-11.)
• Firewalls act as a security buffer between a corporation’s private network and all
external networks, including the Internet. All electronic communications com-
ing into and leaving the corporation must pass through the company’s firewall
where it is evaluated. Security is maintained by denying access to unauthorized
communications.
• Password managers help you create strong passwords. Additionally, they will
store all your passwords in one location and automatically provide the appropriate
password when requested from one of your favorite sites. This avoids many of the
mistakes people make in generating and remembering passwords. However, this
master list of passwords is protected by one ”master” password. If you forget or
reveal this master password, you open yourself up to considerable risk.
Encrypting Data Whenever information is sent over a network or stored on a com-
puter system, the possibility of unauthorized access exists. The solution is encryption,
the process of coding information to make it unreadable except to those who have
Privacy, Security, and Ethics 225
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