Network Working Group H. Nakajima
Internet-Draft Mercari R4D
Intended status: Informational M. Kusunoki
Expires: January 3, 2019 JDD
K. Hida
Y. Suga
Advanced Security Div, IIJ
T. Hayashi
July 02, 2018

Terminology for Crypto Asset


This document provides terminology used in crypto asset.

Status of This Memo

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Table of Contents

1. Introduction

Our goal with this document is to improve our understanding on a set of terms which frequently used in documents which related to crypto asset. Mutual understanding about terminology may help to reach a consensus on issues we’re trying to solve.

2. Conventions and Definitions

The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “NOT RECOMMENDED”, “MAY”, and “OPTIONAL” in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

3. Terms and Definitions

An identifier to represent a public key in a blockchain network.
asymmetric cryptography:
Defined in [RFC4949] as “A modern branch of cryptography (popularly known as “public-key cryptography”) in which the algorithms use a pair of keys (a public key and a private key) and use a different component of the pair for each of two counterpart cryptographic operations (e.g., encryption and decryption, or signature creation and signature verification). “
A basic unit of the blockchain. A set of transactions on a blockchain which contains a cryptographic hash value of previous block.
A digital ledger about transactions for crypto assets.
(For transactions,) checking correctness of a transaction in the mainchain.
Coincidence the way of thinking.
crypto assets:
Cryptographically guaranteed value.
deterministic wallet:
See: wallet
digital signature:
Defined in [RFC4949] as “A value computed with a cryptographic algorithm and associated with a data object in such a way that any recipient of the data can use the signature to verify the data’s origin and integrity.”
distributed ledger:
A distributed database about crypto assets with agreed processed.
double spending:
Defined in [MasteringBitcoinOnline] as “result of successfully spending some money more than once.”
fiat money:
Currency which has been established by government or other authorities.
Defined in [MasteringBitcoinOnline] as “Fork, also known as accidental fork, occurs when two or more blocks have the same block height, forking the block chain. Typically occurs when two or more miners find blocks at nearly the same time.”
genesis block:
An initial block on a blockchain. Genesis block may differ to distinguish chains.
hard fork:
See: fork
hash value:
Defined in [RFC4949] as “The output of a hash function.”
hash rate:
Amount of a hash value which node is able to generate per unit of time (generally per second)
hierarchy deterministic wallet:
See: wallet

A process to append a received transaction to a block by validating a transaction with agreed consensus rules such as proof-of-work and proof-of-stake. Miner is a network node which contributes its resources to mining.
See: mining
Defined in [MasteringBitcoinOnline] as “requiring more than one key to authorize a bitcoin transaction”. In this scope, transaction is not limited to bitcoin transaction.
A device that connects to blockchain network.
off-chain transaction:
The movement of value outside of the blockchain
on-chain transaction:
The movement of value on the blockchain
orphan block:
Defined in [MasteringBitcoinOnline] as “Blocks whose parent block has not been processed by the local node, so they can’t be fully validated yet.”
A public blockchain that only specified members can join the blockchain network.
See: permissioned-chain
An open blockchain that anyone can retrieve all of blocks and transactions without special privileges.
public key:
Defined in [RFC4949] as “The publicly disclosable component of a pair of cryptographic keys used for asymmetric cryptography.”
In contrast with “public-chain”, A closed blockchain that only permissioned users can access blocks and make transactions.
private key:
Defined in [RFC4949] as “The secret component of a pair of cryptographic keys used for asymmetric cryptography.”

Defined in [MasteringBitcoinOnline] as “method by which a cryptocurrency blockchain network aims to achieve distributed consensus.”
Defined in [MasteringBitcoinOnline] as “A piece of data that requires significant computation to find.”
Invalidation process of branched blockchains.
Value by the blockchain network which assigned to a miner who successfully validates a transaction. Rules may differ among blockchains and consensus rules.
See off-chain
smart contract:
A guaranteed digital procedure that automatically enforced on a blockchain network.
soft fork:
See: fork

An unforgeable data object.
Defined in [MasteringBitcoinOnline] as “More precisely, a transaction is a signed data structure expressing a transfer of value.”
Checking correctness and consistency of given data.
See: validation
See: validation
A set of key pair composed of public key and private key.

4. Security Considerations

This document defines terminology for crypto asset. Therefore, there is no security considerations.

5. IANA Considerations


6. References

6.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017.

6.2. Informative References

[MasteringBitcoinOnline] Antonopoulos, A., "Mastering Bitcoin", March 2018.
[RFC4949] Shirey, R., "Internet Security Glossary, Version 2", FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007.


Thanks to members of the Virtual Currency Governance Task Force for help and feedback.

Authors' Addresses

Hirotaka Nakajima Mercari, Inc. R4D Roppongi Hills Mori Tower 18F 6-10-1 Roppongi Minato, Tokyo, 106-6118 JAPAN EMail:
Masanori Kusunoki Japan Digital Design, Inc. EMail:
Keiichi Hida Japan Blockchain Association EMail:
Yuji Suga Advanced Security Division, Internet Initiative Japan Inc. Iidabashi Grand Bloom, 2-10-2 Fujimi Chiyoda, Tokyo, 102-0071 JAPAN EMail:
Tatsuya HAYASHI Lepidum Co. Ltd. EMail: