National foreword

This British Standard is the UK implementation of ISO 11568:2023. It supersedes BS ISO 11568‑4:2007, BS ISO 11568‑2:2012, and BS ISO 11568‑1:2005, which are withdrawn.

The UK participation in its preparation was entrusted to Technical Committee IST/12, Financial services.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 March 2023.

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

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 ISO documents 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 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 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 Technical Committee ISO/TC 68, Financial services, Subcommittee SC 2, Financial services, security.

This document cancels and replaces the former ISO 11568 series, which has been technically revised.

The main changes are as follows:

all parts of the series combined into a single document;
fixed key no longer included in the permissible methods of transaction key management;
required key replacement policy (see 4.13) added;
cleartext key injection removed;
AES DUKPT introduced as a key management method.

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.

Introduction

Retail financial transactions are often transmitted over potentially non-secure channels, which, if exploited, can result in fraud. The vast range in value and volume of such transactions exposes participants to severe risks, which can be uninsurable. To protect against these risks, many institutions are employing encryption. The encryption algorithms used are in the public domain. The security and reliability of any process based on these algorithms is directly dependent on the protection afforded to secrets called cryptographic keys.

This document describes requirements and provides guidance for the secure management of cryptographic keys used to protect sensitive information in a retail financial services environment, for example in messages between a card acceptor and an Acquirer. Typical services in the retail financial services domain include point-of-sale (POS) debit and credit authorizations and automated teller machine (ATM) transactions. While it is designed with these environments in mind, it may also be used in unrelated applications. For example, such keys could be used for:

encrypting Personal Identification Numbers (PIN) (see ISO 9564‑1);
authenticating messages;
encrypting other data;
encrypting or deriving cryptographic keys;
automated symmetric key distribution using asymmetric techniques.

1 Scope

1.1 General

This document describes the management of symmetric and asymmetric cryptographic keys that can be used to protect sensitive information in financial services related to retail payments. The document covers all aspects of retail financial services, including connections between a card-accepting device and an Acquirer, between an Acquirer and a card Issuer, and between an ICC and a card-accepting device. It covers all phases of the key life cycle, including the generation, distribution, utilization, archiving, replacement and destruction of the keying material. This document covers manual and automated management of keying material, and any combination thereof, used for retail financial services. It includes guidance and requirements related to key separation, substitution prevention, identification, synchronization, integrity, confidentiality and compromise, as well as logging and auditing of key management events.

Requirements associated with hardware used to manage keys have also been included in this document.

1.2 Scope exclusions

This document does not specifically address internet banking services offered by an Issuer to their own customers through that financial institution's website or applications.

This document does not address using asymmetric keys to encrypt the Personal Identification Number (PIN) or any other data and does not address asymmetric keys managed with asymmetric keys.

This document is not intended to apply to the management of the keys installed in an ICC during manufacturing or the initial key established in an ICC during card personalization.

This document is not intended to address post-quantum encryption considerations. Key management using quantum technologies is out of scope of this document.

2 Normative references

3 Terms and definitions

4 Key management requirements

4.1 General

4.2 Secure cryptographic device

4.3 Additional CA requirements

4.4 Additional RA requirements

4.5 Key blocks

4.6 Key creation

4.7 Key component and key share creation

4.8 Check values

4.9 Key distribution

4.10 Key loading

4.11 Key utilization

4.12 Key storage

4.13 Key replacement

4.14 Key destruction

4.15 Key backup

4.16 Key archiving

4.17 Key compromise

5 Transaction key management techniques

5.1 General

5.2 Method: master keys or transaction keys

5.3 Derived unique key per transaction

5.4 Host-to-host UKPT

Bibliography

BS ISO 11568:2023

Financial services. Key management (retail)

Current

Published:

31 Mar 2023