ISO/IEC 20543:2019
(Main)Information technology — Security techniques — Test and analysis methods for random bit generators within ISO/IEC 19790 and ISO/IEC 15408
Information technology — Security techniques — Test and analysis methods for random bit generators within ISO/IEC 19790 and ISO/IEC 15408
This document specifies a methodology for the evaluation of non-deterministic or deterministic random bit generators intended to be used for cryptographic applications. The provisions given in this document enable the vendor of an RBG to submit well-defined claims of security to an evaluation authority and shall enable an evaluator or a tester, for instance a validation authority, to evaluate, test, certify or reject these claims. This document is implementation-agnostic. Hence, it offers no specific guidance on design and implementation decisions for random bit generators. However, design and implementation issues influence the evaluation of an RBG in this document, for instance because it requires the use of a stochastic model of the random source and because any such model is supported by technical arguments pertaining to the design of the device at hand. Random bit generators as evaluated in this document aim to output bit strings that appear evenly distributed. Depending on the distribution of random numbers required by the consuming application, however, it is worth noting that additional steps can be necessary (and can well be critical to security) for the consuming application to transform the random bit strings produced by the RBG into random numbers of a distribution suitable to the application requirements. Such subsequent transformations are outside the scope of evaluations performed in this document.
Technologies de l'information — Techniques de sécurité — Méthodes d'essai et d'analyse des générateurs de bits aléatoires dans l'ISO/IEC 19790 et l'ISO/IEC 15408
General Information
Standards Content (Sample)
INTERNATIONAL ISO/IEC
STANDARD 20543
First edition
2019-10
Information technology — Security
techniques — Test and analysis
methods for random bit generators
within ISO/IEC 19790 and ISO/IEC
Technologies de l'information — Techniques de sécurité — Méthodes
d'essai et d'analyse des générateurs de bits aléatoires dans l'ISO/IEC
19790 et l'ISO/IEC 15408
Reference number
©
ISO/IEC 2019
© ISO/IEC 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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ii © ISO/IEC 2019 – All rights reserved
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 7
5 Structure of this document . 7
6 Overview of non-deterministic random bit generators . 7
6.1 Introductory remarks on random bit generation . 7
6.2 Modelling of random sources . 8
6.2.1 Stochastic models . . 8
6.2.2 Heuristic analysis of entropy sources .10
6.2.3 Physical and non-physical sources .11
6.2.4 Overview of the evaluation of the random source of a TNRBG .11
6.2.5 Overview of the evaluation of the random source of an NNRBG.12
6.3 General design template and taxonomy for non-deterministic random bit generators .12
6.3.1 Overview .12
6.3.2 Functional model of a NRBG .12
6.3.3 Components of a NRBG .15
7 Conformance testing of NRBG .18
7.1 Overview .18
7.2 Testing .19
7.2.1 Design documentation .19
7.2.2 Analysing entropy .19
7.2.3 Min entropy .23
7.2.4 Statistical tests .24
7.3 Evaluation .25
7.3.1 General.25
7.3.2 Vendor input to conformance testing .25
8 Overview of deterministic random bit generators .27
8.1 General remarks .27
8.2 Structural overview of a deterministic random bit generator .28
9 Conformance testing of DRBG .29
9.1 Overview .29
9.2 Testing .29
9.2.1 Design documentation .29
9.2.2 Analysis of seed entropy .29
10 Testing methodology .30
10.1 General .30
10.2 Vendor requirements .30
10.3 Tests requirements .30
Annex A (normative) General statistical methodology .31
Annex B (informative) Test files .38
Bibliography .39
© ISO/IEC 2019 – All rights reserved iii
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that
are members of ISO or IEC participate in the development of International Standards through
technical committees established by the respective organization to deal with particular fields of
technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other
international organizations, governmental and non-governmental, in liaison with ISO and IEC, also
take part in the work.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for
the different types of document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent
rights. Details of any patent rights identified during the development of the document will be in the
Introduction and/or on the ISO list of patent declarations received (see www .iso .org/patents) or the IEC
list of patent declarations received (see http: //patents .iec .ch).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso
.org/iso/foreword .html.
This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 27, IT security techniques.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO/IEC 2019 – All rights reserved
Introduction
Cryptographic applications need random numbers for a wide range of tasks. A strong cryptographic
random bit generator that is suitable for general cryptographic applications is expected to provide
output bit strings that cannot be distinguished with any potentially practical computational effort and
any potentially practical sample sizes from bit strings of the same length drawn uniformly at random.
Furthermore, such an RBG is expected to offer enhanced backward secrecy and enhanced forward
secrecy.
© ISO/IEC 2019 – All rights reserved v
INTERNATIONAL STANDARD ISO/IEC 20543:2019(E)
Information technology — Security techniques — Test and
analysis methods for random bit generators within ISO/IEC
19790 and ISO/IEC 15408
1 Scope
This document specifies a methodology for the evaluation of non-deterministic or deterministic
random bit generators intended to be used for cryptographic applications. The provisions given in
this document enable the vendor of an RBG to submit well-defined claims of security to an evaluation
authority and shall enable an evaluator or a tester, for instance a validation authority, to evaluate, test,
certify or reject these claims.
This document is implementation-agnostic. Hence, it offers no specific guidance on design and
implementation decisions for random bit generators. However, design and implementation issues
influence the evaluation of an RBG in this document, for instance because it requires the use of a
stochastic model of the random source and because any such model is supported by technical arguments
pertaining to the design of the device at hand.
Random bit generators as evaluated in this document aim to output bit strings that appear evenly
distributed. Depending on the distribution of random numbers required by the consuming application,
however, it is worth noting that additional steps can be necessary (and can well be critical to security)
for the consuming application to transform the random bit strings produced by the RBG into random
numbers of a distribution suitable to the application requirements. Such subsequent transformations
are outside the scope of evaluations performed in this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 15408 (all parts), Information technology — Security techniques — Evaluation criteria for IT
security
ISO/IEC 17825, Information technology — Security techniques — Testing methods for the mitigation of
non-invasive attack classes against cryptographic modules
ISO/IEC 18031:2011, Information technology — Security techniques — Random bit generation
ISO/IEC 19790, Information technology — Security techniques — Security requirements for
cryptographi
...
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