GlossaireFR

Tokenisation

La tokenisation désigne la création d’une nouvelle catégorie
de jetons dans une blockchain pour déployer une économie
propre à un écosystème. La tokenisation est souvent conçue de
manière à créer des mesures incitatives pour les contributeurs
et usagers de l’écosystème. Le phénomène de tokenisation
s’inscrit en partie en réaction au phénomène de perte de
confiance dans les devises et monnaies étatiques officielles.

Voir : Jeton 54

Blockchain

A blockchain is a distributed ledger based on a data structure
called a blockchain. Transactions are stored in blocks that
are chained to each other. A block contains, in addition to
transactions, the hash of the previous block. The modification
of a transaction therefore modifies not only the block to which
it belongs but all the blocks that follow it. The blockchain
structure gives the distributed ledger its immutability.

Often, by abuse of language, blockchain refers to any type of
distributed ledger and not only those that are based on a chain
of blocks.

See: Distributed ledger, Hash, Immutability 11

Tolérance aux fautes
byzantines

La tolérance aux fautes byzantines est une caractéristique
d’algorithmes qui permettent d’éviter les difficultées liées au
problème des généraux byzantins, selon lequel, en l’absence
de liens de confiance entre les participants, deux tiers de ces
derniers doivent agir (ou plus exactement avoir intérêt à agir)
de manière honnête pour que le consensus ne soit pas biaisé.
Pour éviter les défaillances dans un écosystème décentralisée,
les algorithmes de consensus de blockchains doivent être
tolérants aux fautes byzantines.

Voir : Algorithme de consensus, Décentralisaiton 55

Bitcoin

Bitcoin (with a capital letter) designates the first blockchain whose
description was published in 2008 under the name “Bitcoin: A
Peer-to-Peer Electronic Cash System” by an anonymous author.

Bitcoin (with a lowercase) refers to the digital asset transferred
on the Bitcoin blockchain. The total number of bitcoins has been
set arbitrarily by its creator to 21 million. These are currently
issued at a rate of 12.5 bitcoins approximately every 10 minutes
and are used to reward the miner who formed the most recent
block. The consensus algorithm of the Bitcoin network is proof
of work.

See: Consensus algorithm 10

Traçabilité

La traçabilité désigne la possibilité de suivre un parcours
soit de manière continue à distance grâce à un système de
géolocalisation connecté soit a posteriori à partir de traces
horodatées intégrées lors du parcours. La technologie
blockchain permet de limiter les risques d’altération unilatérale
des données et d’assurer un degré de transparence élevé.

Voir : Horodatage, Transparence 56

Asymmetric
cryptography

Asymmetric cryptography is the most used cryptography branch
in the blockchain space. It relies on two keys owned by each
participant: a private key kept secret by its owner and a public
key that can be widely distributed.

For example, if A wants to send a message readable only by
B, then A encrypts his message with the public key of B. This
message can only be decrypted via the private key of B, of
which B is the only owner.

Note that a private key can also sign a message.

See: Cryptography, Key 9

Transaction

Le registre d’une blockchain est constitué de transactions. La
transaction la plus simple est l’échange d’actifs numériques
d’un noeud à l’autre (A envoie X jetons à B). Une transaction
peut aussi se faire d’un noeud vers un contrat intelligent dans le
cadre de l’exécution d’un contrat intelligent sur une blockchain
programmable comme Ethereum.

Voir : Blockchain, Contrat intelligent, Crypto-actif, Ethereum 57

51% Attack

The 51% attack refers to the attack of a blockchain (with
miners) led by a set of nodes who control more than half of the
computing power of the network. In this case, this set of nodes
can choose the transactions written in the blockchain and make
a double spending possible. It is an attack that is often feared
because it can invalidate the blockchain.

This term is often used in reference to the Bitcoin blockchain.

See: Bitcoin, Mining 8

Transparence

La transparence est une propriété fondamentale de certaines
blockchains (en particulier les blockchains publiques). La
transparence d’une blockchain assure que l’ensemble des
transactions est visible de l’ensemble du réseau. La transparence
permet par exemple d’avoir accès à toutes les transactions de la
blockchain Bitcoin depuis sa création.

Dans le cas de blockchains privées, la transparence peut être
volontairement limitée afin de préserver la confidentialité.

Voir : Bitcoin, Blockchain privée, Pseudonymat 58

blockchain technologies, both on definitions and use cases.
This glossary aims at being a tool to apprehend the event.

The team has selected fifty words shaping the ecosystem
that we hope will allow discussions between the various
stakeholders involved in the blockchain revolution. We
also hope that it can serve as a source of inspiration to the
participants who strive daily to build a better world.

Matthieu QUINIOU
Christophe DEBONNEUIL

Presentation

Technological innovation formalized in the 2000s, blockchain
has become an essential tool over the years. Glorified
spreadsheet or ultimate form of democracy? The reality
probably lies somewhere in the middle.

Blockchain technologies are still at an early stage but already,
use cases flourish including in education and science.
Moreover, the moment is well chosen : after a long period
of testing, 2019 promises to be the year of production for
many projects.

The Blockchain day organized by UNESCO and the UNESCO
ITEN Chair provides an overview of the situation on

Matthieu QUINIOU
Attorney at law (Paris Bar), Ph.D, holder
of the AMF certification, researcher at
the UNESCO Chair ITEN (UP8/FMSH) and
member of the AFNOR/ISO Committee on
blockchain.

Christophe DEBONNEUIL
Graduated from HEC, engineer from Ecole
Centrale de Lyon. Graduated from Said
Business School on blockchain, Oxford
University. In charge of trainings at OECD on
blockchain technologies.

John MOTTA
Art director, researcher at the UNESCO Chair
ITEN (UP8/FMSH), working on graphical
representation of concepts and teaching at
the Master CEN/UP8.

Hyperledger................................. 28 Public blockchain.........................46
Immutability................................ 29 Scalability..................................... 47
Initial Coin Offering (ICO)............ 30 Self-sovereign identity................. 48
Internet of value..........................31 Side chain.....................................49
Interoperability............................ 32 Smartcontract.............................. 50
Time-stamping............................. 51
Chronology �������������������������������� 33 Token............................................ 52
Key................................................ 34 Tokenization................................. 53
Mining.......................................... 35 Traceability................................... 54
Node............................................ 36 Transaction.................................. 55
Non fungible token......................37 Transparency............................... 56
Open source................................38 Wallet........................................... 57
Oracle........................................... 39 Zero Knowledge Proof (ZKP)....... 58
Peer-to-peer network................. 40
Private blockchain.......................41
Proof of authority (PoA).............. 42
Proof of stake (PoS).....................43
Proof of work (PoW)....................44
Pseudonymity.............................. 45

Summary

Presentation................................ 6 Decentralized Application
51% attack..................................... 8 (dApp).......................................... 18
Asymmetric cryptography............. 9 Decentralized Autonomous
Bitcoin.......................................... 10 Organisation (DAO).....................19
Blockchain.................................... 11 Digital signature...........................20
Byzantine fault tolerance............ 12 Disintermediation........................ 21
Consensus algorithm...................13 Distributed ledger.......................22
Crypto-asset................................ 14 Double spending problem.......... 23
Cryptography............................... 15 Ethereum..................................... 24
Cypherpunk................................. 16 Fork.............................................. 25
Decentralization.......................... 17 Governance................................. 26
Hash............................................. 27

Authors : Published by :
Matthieu QUINIOU
Christophe DEBONNEUIL 17, rue de Lancry 75010 Paris (France)

Cover graphic concept: The project CréaTIC / ANR-11-
Unesco IDFI-0011 under Investments for
the Future.
Interior layout:
John Motta

ISBN : 979-10-91636-18-6

Printend, April 2019
© Chaire UNESCO ITEN, 2019

GLOSSARY

Blockchain

Matthieu QUINIOU
Christophe DEBONNEUIL