ISO/IEC 18370-2:2016
(Main)Information technology — Security techniques — Blind digital signatures — Part 2: Discrete logarithm based mechanisms
Information technology — Security techniques — Blind digital signatures — Part 2: Discrete logarithm based mechanisms
ISO/IEC 18370-2:2016 specifies blind digital signature mechanisms, together with mechanisms for three variants of blind digital signatures. The variants are blind digital signature mechanisms with partial disclosure, blind digital signature mechanisms with selective disclosure and traceable blind digital signature mechanisms. The security of all the mechanisms in ISO/IEC 18370-2:2016 is based on the discrete logarithm problem. For each mechanism, ISO/IEC 18370-2:2016 specifies the following: - the process for generating the keys of the entities involved in these mechanisms; - the process for producing blind signatures; - the process for verifying signatures. ISO/IEC 18370-2:2016 specifies another process specific to blind signature mechanisms with selective disclosure, namely, the following: - the presentation process. Furthermore, ISO/IEC 18370-2:2016 specifies other processes specific to traceable blind signature mechanisms, namely, the following: a) the process for tracing requestors; b) the process for tracing signatures; c) the requestor tracing evidence evaluation process (optional); d) the signature tracing evidence evaluation process (optional).
Technologie de l'information — Techniques de sécurité — Signatures numériques en aveugle — Partie 2: Mécanismes fondés sur le logarithme discret
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Standards Content (Sample)
DRAFT INTERNATIONAL STANDARD
ISO/IEC DIS 18370-2
ISO/IEC JTC 1/SC 27 Secretariat: DIN
Voting begins on: Voting terminates on:
2015-02-09 2015-05-09
Information technology — Security techniques — Blind
digital signatures —
Part 2:
Discrete logarithm based mechanisms
Technologie de l’information — Techniques de sécurité — Signatures numériques en aveugle —
Partie 2: Mécanismes fondés sur le logarithme discret
ICS: 35.040
THIS DOCUMENT IS A DRAFT CIRCULATED
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Reference number
NATIONAL REGULATIONS.
ISO/IEC DIS 18370-2:2014(E)
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NOTIFICATION OF ANY RELEVANT PATENT
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©
PROVIDE SUPPORTING DOCUMENTATION. ISO/IEC 2014
ISO/IEC DIS 18370-2:2014(E)
© ISO/IEC 2014
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
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Published in Switzerland
ii © ISO/IEC 2014 – All rights reserved
ISO/IEC DIS 18370-2
Contents Page
Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and abbreviated terms . 3
5 General requirements . 4
6 Blind signature mechanisms . 4
6.1 General . 4
6.2 Mechanism 1 . 4
6.2.1 Security parameters . 4
6.2.2 Key generation process . 4
6.2.3 Blind signature process. 5
6.2.4 Verification process . 6
7 Blind signature mechanisms with partial disclosure . 6
7.1 General . 6
7.2 Mechanism 2 . 6
7.2.1 Security parameters . 6
7.2.2 Key generation process . 6
7.2.3 Blind signature process with partial disclosure . 7
7.2.4 Verification process . 8
7.3 Mechanism 3 . 8
7.3.1 Symbols . 8
7.3.2 Key generation process . 8
7.3.3 Blind signature process with partial disclosure . 9
7.3.4 Verification process . 10
8 Blind signature mechanisms with selective disclosure . 10
8.1 General . 10
8.2 Mechanism 4 . 10
8.2.1 Security parameters . 10
8.2.2 Key generation process . 10
8.2.3 Blind signature process with selective disclosure . 11
8.2.4 Presentation process . 12
8.2.5 Verification process . 13
9 Traceable blind signature mechanisms . 13
9.1 General . 13
9.2 Mechanism 5 . 14
9.2.1 Symbols . 14
9.2.2 Key generation process . 14
9.2.3 Traceable blind signature process . 15
9.2.4 Verification process . 17
9.2.5 Requestor tracing process . 17
9.2.6 Signature tracing process . 18
9.2.7 Requestor tracing evidence evaluation process . 18
9.2.8 Signature tracing evidence evaluation process . 18
Annex A (normative) Object identifiers . 20
Annex B (normative) Conversion functions . 21
© ISO/IEC 2014 – All rights reserved iii
ISO/IEC DIS 18370-2
B.1 Conversions between bit strings and integers: BS2IP and I2BSP .21
Annex C (normative) Group description .22
Annex D (informative) Special hash functions .23
D.1 Hash function with larger output length: HL .23
D.2 Hashing to an element of a prime field: HBS2PF .23
D.3 Hashing to a point on an elliptic curve: HBS2ECP .23
D.4 Hashing to an element of a cyclic group: HBS2CG .23
Annex E (informative) Security considerations and comparison of blind signature mechanisms .25
E.1 Descriptions of mathematical assumptions .25
E.1.1 General .25
E.1.2 The discrete logarithm (DL) assumption .25
E.1.3 The decisional Diffie-Hellman (DDH) assumption .25
E.2 Guidance for parameters choice .25
E.2.1 Key sizes .25
E.2.2 Hash algorithm selection and digest sizes .25
E.2.3 Random number generation .26
E.3 Symbols and abbreviated terms for comparing each mechanism .26
E.4 Comparison of each mechanism .26
Annex F (informative) Numerical examples .27
F.1 Mechanism 1 .27
F.1.1 Generation of domain parameters .27
F.1.2 Generation of signature key and verification key .28
F.1.3 Blind signature process .29
F.1.4 Verification process .31
F.2 Mechanism 2 .31
F.2.1 Finite field based domain parameters .31
F.2.2 Elliptic curve based domain parameters .36
F.3 Mechanism 3 .38
F.3.1 Finite field based domain parameters .38
F.3.2 Elliptic curve based domain parameters .42
F.4 Mechanism 4 .44
F.4.1 Finite field based domain parameters .44
F.4.2 Elliptic curve based domain parameters .46
F.5 Mechanism 5 .48
F.5.1 Finite field based domain parameters .48
F.5.2 Elliptic curve based domain parameters .62
Bibliography .68
iv © ISO/IEC 2014 – All rights reserved
ISO/IEC DIS 18370-2
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
...
INTERNATIONAL ISO/IEC
STANDARD 18370-2
First edition
2016-07-01
Information technology — Security
techniques — Blind digital
signatures —
Part 2:
Discrete logarithm based mechanisms
Technologie de l’information — Techniques de sécurité — Signatures
numériques en aveugle —
Partie 2: Mécanismes fondés sur le logarithme discret
Reference number
©
ISO/IEC 2016
© ISO/IEC 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO/IEC 2016 – All rights reserved
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 3
5 General requirements . 4
6 Blind signature mechanisms . 4
6.1 General . 4
6.2 Mechanism 1 . 4
6.2.1 Security parameters . 4
6.2.2 Key generation process . 5
6.2.3 Blind signature process. 5
6.2.4 Verification process . 6
7 Blind signature mechanisms with partial disclosure . 6
7.1 General . 6
7.2 Mechanism 2 . 6
7.2.1 Security parameters . 6
7.2.2 Key generation process . 6
7.2.3 Blind signature process with partial disclosure . 7
7.2.4 Verification process . 8
7.3 Mechanism 3 . 8
7.3.1 Symbols . 8
7.3.2 Key generation process . 8
7.3.3 Blind signature process with partial disclosure . 9
7.3.4 Verification process . 9
8 Blind signature mechanisms with selective disclosure .10
8.1 General .10
8.2 Mechanism 4 .10
8.2.1 Security parameters .10
8.2.2 Key generation process .10
8.2.3 Blind signature process with selective disclosure .10
8.2.4 Presentation process .12
8.2.5 Verification process .12
9 Traceable blind signature mechanisms .13
9.1 General .13
9.2 Mechanism 5 .13
9.2.1 Symbols .13
9.2.2 Key generation process .13
9.2.3 Traceable blind signature process .14
9.2.4 Verification process .16
9.2.5 Requestor tracing process .16
9.2.6 Signature tracing process .17
9.2.7 Requestor tracing evidence evaluation process .17
9.2.8 Signature tracing evidence evaluation process .17
Annex A (normative) Object identifiers .19
Annex B (normative) Conversion functions .20
Annex C (normative) Group description .21
Annex D (informative) Special hash-functions.22
© ISO/IEC 2016 – All rights reserved iii
Annex E (informative) Security considerations and comparison of blind signature mechanisms .24
Annex F (informative) Numerical examples .26
Bibliography .78
iv © ISO/IEC 2016 – All rights reserved
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. In the field of information technology, ISO and IEC have established a joint technical committee,
ISO/IEC JTC 1.
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).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/IEC JTC 1, Information technology, Subcommittee
SC 27, IT Security techniques.
ISO/IEC 18370 consists of the following parts, under the general title Information technology — Security
techniques — Blind digital signatures:
— Part 1: General
— Part 2: Discrete logarithm based mechanisms
Further parts may follow.
© ISO/IEC 2016 – All rights reserved v
Introduction
Blind digital signature mechanisms are a special type of digital signature mechanism, as specified in
ISO/IEC 9796 (all parts) and ISO/IEC 14888, which allow a user (a requestor) to obtain a signature from
a signer of the user’s choice, without giving the signer any information about the message that is signed
or the resulting signature.
In some mechanisms, the signer does not completely lose control over the signed message since the
signer can include explicit information in the resulting signature under an agreement with the
requestor. These types of blind signatures are called blind signatures with partial disclosure.
Other mechanisms allow a requestor to receive a blind signature on a message not known to the signer
but the choice of the message is restricted and needs to conform to certain rules. Such mechanisms are
called blind signature mechanisms with selective disclosure.
Depending on the mechanism, it may be possible for an authorized entity to trace a signature to the
requestor who requested it. Such an entity can either identify a signature that resulted from a given
signature request (signature tracing), or link a signature to the receiver who requested it (requestor
tracing). Blind signature mechanisms with tracing features are called traceable blind signature
mechanisms.
ISO/IEC 18370 specifies blind digital signature mechanisms, as well as three variants: blind digital
signature mechanisms wit
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