ISO/IEC 30136:2018 情報技術—生体認証テンプレート保護スキームのパフォーマンステスト | ページ 6

3.1

accuracy degradation

difference in FNMR/FMR (or FAR/FRR) for a biometric system tested both with and without template protection schemes

3.2

adversary

one who compromises an enrolment database and may gain access to the generative biometric data of the individuals enrolled therein

3.3

biometric template protection

protection of biometric references under various requirements for secrecy, irreversibility, and renewability during storage and transfer

3.4

generative biometric data

biometric data (sample(s) or features) used as primary input to the biometric template protection scheme

3.5

irreversibility

property of a transform that creates a biometric reference from generative biometric data such that knowledge of the transformed biometric reference cannot be used to determine any information about the generative biometric data

Note 1 to entry: Metrics introduced by this document aim to measure irreversibility by the degree of difficulty faced by an adversary in recreating an original unprotected version of the biometric data.

3.6

privacy compromise

event in which an adversary discovers part of the generative biometric data of an individual enrolled in the database of a biometric verification or identification system

Note 1 to entry: Discovery of part of the generative biometric data does not mean that successful biometric recognition is achieved, i.e. biometric system secrecy is not compromised by the discovery itself.

3.7

privacy leakage

<template protection scheme> amount of information about an individual‘s generative biometric data which an adversary can learn from the stored reference data

3.8

pseudonymous identifier comparator

system, process or algorithm that compares the pseudonymous identifier generated during enrolment by the pseudonymous identifier encoder and the pseudonymous identifier reconstructed during verification by the pseudonymous identifier recoder, and returns a similarity score representing the similarity between the two

3.9

pseudonymous identifier recoder

system, process or algorithm that reconstructs a pseudonymous identifier based on the provided auxiliary data and the extracted features

3.10

secrecy

degree of difficulty faced by an adversary in determining input data, from a protected biometric template, that achieves biometric recognition, when impersonating an individual enrolled in the biometric enrolment database of a template protection system

3.11

secrecy compromise

event in which an adversary achieves biometric recognition when impersonating an individual enrolled in the biometric enrolment database of a template protection system

Note 1 to entry: Secrecy compromise includes the case in which the adversary gains unlawful access without necessarily discovering the generative biometric data of the individual being impersonated, i.e. the case in which the adversary remains unable to cause a privacy compromise.

3.12

successful attack rate

probability that an informed adversary can obtain a false accept result in a biometric system

Note 1 to entry: An informed adversary is one that has compromised (gained access to) a subset of the biometric enrolment database and the secret parameters (if any) associated with one or more biometric recognition systems (potentially including the target system under consideration) in which common individuals are enrolled.

3.13

template diversity

expected value of the number of independent protected templates that can be generated from a given generative biometric data by a biometric template protection scheme

3.14

template size

size of stored reference data

3.15

unlinkability

property of two or more biometric references that they cannot be linked to each other or to the subject(s) from which they were derived