ISO 24138:2024 情報とドキュメント — 国際標準内容コード (ISCC) | ページ 6

3.1

bit

atomic unit of information in a computer system

3.2

byte

sequence of 8 bits (3.1)

3.3

nibble

half a byte (3.2) , which can be represented by a single hexadecimal digit

[SOURCE:ISO 20038:2017, 3.12]

3.4

data

ordered sequence of bits (3.1)

3.5

file

stored data (3.4) with a known number of bits (3.1) and a filename

3.6

stream

data (3.4) in transit with a known or unknown number of bits (3.1)

3.7

content

information organized to provide value to a user

3.8

digital content

manifestation of content (3.7) in form of data (3.4) structured according to a set of rules

3.9

metadata

data (3.4) that defines and describes other data

[SOURCE:ISO 24531:2013, 4.32]

3.10

seed metadata

initial metadata (3.9) used as input to a hash algorithm (3.1) function

3.11

content format

set of rules used to structure digital content (3.8)

3.12

media type

two-part identifier (3.15) specifying the nature of the referenced data (3.4)

[SOURCE:ISO/IEC 19757-4:2006, 3.9]

3.13

digital asset

file (3.5) or stream (3.6) encoded in conformance with a specific content format (3.11)

3.14

referent

object which is identified

3.15

identifier

sequence of characters that uniquely denotes a referent (3.14)

3.16

identifier system

system to enable the provision of identifiers (3.15) for a given category of referents (3.14)

3.17

content identifier

identifier (3.15) whose referent (3.14) is content (3.7)

3.18

content-dependent identifier

content identifier (3.18) whose data (3.4) depends on the digital content (3.8) that it identifies

3.19

content recognition system

system whose primary purpose is to recognise digital content (3.8) on a granular level

3.20

algorithm

set of instructions

3.21

hash algorithm

deterministic algorithm (3.20) that produces fixed-length data (3.4) from an input of arbitrary-length data

3.22

hash digest

result of processing data (3.4) with a hash algorithm (3.21)

3.23

cryptographic hash function

computationally efficient function mapping binary strings of arbitrary length to binary strings of fixed length, such that it is computationally infeasible to find two distinct values that hash into a common value

3.24

similarity hash

hash digest (3.22) that preserves correlations between inputs to the hash algorithm (3.21)

3.25

content defined chunking

CDC

method to split data (3.4) into variable length chunks based on internal features such that chunk boundaries are more resistant to byte (3.2) shifting

3.26

actor

human or non-human (hardware or software) entity that interacts with a system

3.27

Merkle tree

tree data structure in which every leaf node is labelled with the hash digest (3.22) of a data element and every non-leaf node is labelled with the hash digest of the labels of its child nodes

3.28

Merkle root

root node of a Merkle tree (3.27)

[SOURCE:ISO 22739:2024, 3.57]

3.29

ISCC processor

application that generates ISCCs for digital content (3.8)

3.30

plain text

data (3.4) with a known text encoding that can be transcoded to Unicode

3.31

whitespace

nondisplaying formatting characters such as spaces, tabs, etc., that are embedded within a block of free text

[SOURCE:ISO/IEC/IEEE 31320-2:2012, 3.1.210]