ISO/IEC Information technology Security techniques Key management Part 3: Mechanisms using asymmetric techniques

Transcription

1 INTERNATIONAL STANDARD ISO/IEC First edition Information technology Security techniques Key management Part 3: Mechanisms using asymmetric techniques Technologies de l'information Techniques de sécurité Gestion de clés Partie 3: Mécanismes utilisant des techniques asymétriques Reference number ISO/IEC 1999

2 This is a preview - click here to buy the full publication PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. ISO/IEC 1999 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel Fax copyright@iso.ch Web Printed in Switzerland ii ISO/IEC 1999 All rights reserved

3 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. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote. Attention is drawn to the possibility that some of the elements of this part of ISO/IEC may be the subject of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. International Standard ISO/IEC was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 27, IT Security techniques. ISO/IEC consists of the following parts, under the general title Information technology Security techniques Key management: Part1:Framework Part 2: Mechanisms using symmetric techniques Part 3: Mecanisms using asymmetruc techniques Further parts may follow. Annexes A to E of this part of ISO/IEC are for information only. ISO/IEC 1999 All rights reserved iii

4 INTERNATIONAL STANDARD Information technology Security techniques Key management Part 3: Mechanisms using asymmetric techniques 1. Scope This part of ISO/IEC defines key management mechanisms based on asymmetric cryptographic techniques. It specifically addresses the use of asymmetric techniques to achieve the following goals: 1. Establish a shared secret key for a symmetric cryptographic technique between two entities A and B by key agreement. In a secret key agreement mechanism the secret key is the result of a data exchange between the two entities A and B. Neither of them can predetermine the value of the shared secret key. 2. Establish a shared secret key for a symmetric cryptographic technique between two entities A and B by key transport. In a secret key transport mechanism the secret key is chosen by one entity A and is transferred to another entity B, suitably protected by asymmetric techniques. 3. Make an entity's public key available to other entities by key transport. In a public key transport mechanism, the public key of an entity A must be transferred to other entities in an authenticated way, but not requiring secrecy. Some of the mechanisms of this part of ISO/IEC are based on the corresponding authentication mechanisms in ISO/IEC This part of ISO/IEC does not cover aspects of key management such as - key lifecycle management, - mechanisms to generate or validate asymmetric key pairs, - mechanisms to store, archive, delete, destroy, etc. keys. While this part of ISO/IEC does not explicitly cover the distribution of an entity's private key (of an asymmetric key pair) from a trusted third party to a requesting entity, the key transport mechanisms described can be used to achieve this. This part of ISO/IEC does not cover the implementations of the transformations used in the key management mechanisms. NOTE - To achieve authenticity of key management messages it is possible to make provisions for authenticity within the key establishment protocol or to use a public key signature system to sign the key exchange messages. 2. Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of ISO For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this part of ISO are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO/IEC 1999 All rights reserved 1

5 This is a preview - click here to buy the full publication ISO :1989, Information processing systems - Open Systems Interconnection - Basic Reference Model - Part 2: Security Architecture. ISO/IEC :1995, Information technology - Open Systems Interconnection The Directory: Authentication framework. ISO/IEC :1998, Information technology - Security techniques - Entity authentication - Part 3: Mechanisms using digital signature techniques. ISO/IEC :1994, Information technology - Security techniques - Hash-functions - Part 1: General. ISO/IEC :1996, Information technology - Open Systems Interconnection - Security frameworks for open systems Overview. ISO/IEC :1996, Information technology - Security techniques - Key management - Part 1: Framework. transformation suffices for both signing and decrypting messages, and one public transformation suffices for both verifying and encrypting messages. However, since this does not conform to the principle of key separation, throughout this part of ISO/IEC the four elementary transformations and the corresponding keys are kept separate asymmetric encipherment system: a system based on asymmetric cryptographic techniques whose public transformation is used for encipherment and whose private transformation is used for decipherment asymmetric key pair: a pair of related keys where the private key defines the private transformation and the public key defines the public transformation certification authority (CA): a center trusted to create and assign public key certificates. Optionally, the certification authority may create and assign keys to the entities cryptographic check function: a crypto- 2 ISO/IEC 1999 All rights reserved