ISO/IEC 9594-11:2025
(Main)Information technology — Open systems interconnection directory — Part 11: Protocol specifications for secure operations
Information technology — Open systems interconnection directory — Part 11: Protocol specifications for secure operations
This document provides guidance on how to prepare new and old protocols for cryptographic algorithm migration and defines auxiliary cryptographic algorithms to be used for migration purposes. This document specifies a general wrapper protocol that provides authentication, integrity and confidentiality (encryption) protection for other protocols. This wrapper protocol includes a migration path for cryptographic algorithms allowing for smooth migration to stronger cryptographic algorithms as such requirements evolve. This will allow migration to quantum-safe cryptographic algorithms. Protected protocols can then be developed without taking security and cryptographic algorithms into consideration. This document also includes some protocols to be protected by the wrapper protocol primarily for support of public-key infrastructure (PKI). Other specifications, e.g., Recommendations or International Standards, may also develop protocols designed to be protected by the wrapper protocol.
Technologies de l'information — Interconnexion de systèmes ouverts (OSI) — Partie 11: Titre manque
General Information
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Standards Content (Sample)
International
Standard
ISO/IEC 9594-11
Second edition
Information technology —
2025-08
Open systems interconnection
directory —
Part 11:
Protocol specifications for secure
operations
Reference number
© ISO/IEC 2025
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ii
Foreword
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In the IEC, see www.iec.ch/understanding-standards.
This document was prepared by ITU-T as ITU-T X.510 (10/2023) and drafted in accordance with its editorial
rules, in collaboration with Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee
SC 6, Telecommunications and information exchange between systems.
This second edition cancels and replaces the first edition (ISO/IEC 9594-11:2020), which has been technically
revised.
A list of all parts in the ISO/IEC 9594 series can be found on the ISO and IEC websites.
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 and www.iec.ch/national-
committees.
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CONTENTS
Page
SECTION 1 – GENERAL . 1
1 Scope . 1
2 Normative references . 1
2.1 Identical Recommendations | International Standards . 1
2.2 Paired Recommendations | International Standards equivalent in technical content . 1
2.3 International Standards . 2
2.4 Other references . 2
3 Definitions . 2
3.1 OSI reference model definitions . 2
3.2 Directory model definitions . 2
3.3 Public-key and attribute certificate definitions . 2
3.4 Terms defined in this Recommendation | International Standard . 3
4 Abbreviations . 4
5 Conventions . 5
6 Communication model . 5
7 Common data types and special cryptographic algorithms . 5
7.1 Introduction . 5
7.2 ASN.1 information object class specification tool. 5
7.3 Parameterized data types . 7
7.4 Multiple cryptographic algorithm specifications . 9
7.5 Parameterized data types for providing multiple-cryptographic algorithm-values . 15
7.6 Formal specification of encipherment . 16
8 Symmetric-key algorithms . 17
8.1 Introduction to symmetric-key algorithms . 17
8.2 Advance encryption standard (AES) – symmetric-key algorithms . 18
8.3 Camellia symmetric-key algorithms . 21
8.4 SEED – symmetric-key algorithms . 24
8.5 SM4 – symmetric-key algorithms. 26
9 Public-key and digital signature algorithms . 28
10 Key establishment algorithms . 28
10.1 General . 28
10.2 Diffie-Hellman over prime field . 28
10.3 Elliptic curve Diffie-Hellman . 30
10.4 Key derivation . 31
11 General concepts for securing protocols . 32
11.1 Introduction . 32
11.2 Protected protocol plug-in concept . 32
11.3 Communication structure . 32
11.4 Another view of the relationship between the wrapper protocol and the protected protocol . 33
11.5 Structure of the application protocol data unit . 33
11.6 Exception conditions . 33
SECTION 2 – THE WRAPPER PROTOCOL . 34
12 Wrapper protocol general concepts . 34
12.1 Introduction . 34
12.2 UTC time specification . 34
12.3 Use of alternative cryptographic algorithms . 34
12.4 Establishment of symmetric keys . 34
12.5 Sequence numbers . 35
12.6 Use of invocation identification in the wrapper protocol . 35
12.7 Mapping to underlying services . 35
12.8 Addressing of communicating entities. 35
Rec. ITU-T X.510 (10/2023)
© ISO/IEC 2025 – All rights reserved
iv
12.9 Definition of protected protocols . 35
12.10 Overview of wrapper protocol data units. 35
13 Association management . 36
13.1 Introduction to association management . 36
13.2 Association handshake request . 36
13.3 Association handshake accept . 37
13.4 Association reject due to security issues . 38
13.5 Association reject by the protected protocol . 39
13.6 Handshake security abort . 40
13.7 Handshake abort by protected protocol . 40
13.8 Data transfer security abort . 41
13.9 Abort by protected protocol . 41
13.10 Release request WrPDU . 42
13.11 Release response WrPDU . 42
13.12 Release collision . 43
14 Data transfer phase . 43
14.1 Symmetric keys renewal . 43
14.2 Data transfer by the client . 44
14.3 Data transfer by the server . 45
15 Information flow. 48
15.1 Purpose and general model . 48
15.2 Protected protocol SAOC . 49
15.3 Wrapper SAOC . 49
16 Wrapper error handling .
...
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