National foreword

This British Standard is the UK implementation of ISO/IEC 27099:2022.

The UK participation in its preparation was entrusted to Technical Committee IST/33/4, Security Controls and 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 30 September 2022.

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 or www.iec.ch/members_experts/refdocs).

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 https://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. In the IEC, see www.iec.ch/understanding-standards.

This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 27, Information security, cybersecurity and privacy protection.

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.

Introduction

The business objective of a public key infrastructure (PKI) is to establish and manage trust relationships. The services provided by the PKI should maintain that trust and organizational and technical security measures for an appropriate security level have to be defined and implemented for all entities participating in a PKI.

Institutions and intermediaries are building infrastructures to provide new electronic transaction capabilities for consumers, corporations, and government entities. As the volume of electronic transactions continues to grow, advanced security technology using digital signatures and trust services can become part of the transaction process. Transaction systems incorporating advanced security technology have requirements to ensure the confidentiality, integrity and availability of transactions conducted over communications networks.

Industry relies on several time-honoured methods of electronically identifying, authorizing, and authenticating entities and protecting transactions. These methods include, but are not limited to, personal identification numbers (PINs) and message authentication codes (MACs) for retail and wholesale transactions, user IDs and passwords for network and computer access, and key management for network connectivity. Over the past 30 years, industry has developed risk management processes and policies to support the use of these technologies.

The ubiquitous use of online services in public networks and the needs of the industry in general to provide safe, private, and reliable transaction and computing systems have given rise to advanced security technology incorporating public key cryptography. Public key cryptography requires a business-optimized infrastructure of technology, management, and policy (a public key infrastructure or PKI, as defined in this document) to satisfy requirements of electronic identification, authentication, message integrity protection and authorization in application systems. The use of standard practices for electronic identification, authentication and authorization in a PKI ensures more consistent and predictable security in these systems and confidence in electronic communications. Confidence (e.g. trust) can be achieved when adherence to standard practices can be ascertained.

Applications serving industry can be developed with digital signature and PKI capabilities. The safety and the soundness of these applications are based, in part, on implementations and practices designed to ensure the overall integrity of the infrastructure. Users of authority-based systems that electronically bind the identity of individuals and other entities to cryptographic materials (e.g. cryptographic keys) benefit from standard risk management systems and the base of auditable practices defined in this document.

This document provides a framework for managing a PKI through certificate policies, certification practice statements, control objectives and supporting procedures. The degree to which any entity in a transaction can rely on the implementation of public key infrastructure standards and the extent of interoperability between PKI-based systems will depend partly on factors relative to policy and practices defined in this document.

In some regions or countries there is a legislative framework which defines requirements for operation of PKI and other related trust services to achieve a recognized level of trust for a specific purpose commonly called “qualified”.

This document is derived from ISO 21188:2018, which content has been generalized in this document to be applicable to any application domain and to take into account general standards for information security. See Annex E for a description of major changes to ISO 21188:2018 clauses that have been made in order to produce this document.

1 Scope

This document sets out a framework of requirements to manage information security for Public key infrastructure (PKI) trust service providers through certificate policies, certificate practice statements, and, where applicable, their internal underpinning by an information security management system (ISMS). The framework of requirements includes the assessment and treatment of information security risks, tailored to meet the agreed service requirements of its users as specified through the certificate policy. This document is also intended to help trust service providers to support multiple certificate policies.

This document addresses the life cycle of public key certificates that are used for digital signatures, authentication, or key establishment for data encryption. It does not address authentication methods, non-repudiation requirements, or key management protocols based on the use of public key certificates. For the purposes of this document, the term “certificate” refers to public key certificates. This document is not applicable to attribute certificates.

This document uses concepts and requirements of an ISMS as defined in the ISO/IEC 27000 family of standards. It uses the code of practice for information security controls as defined in ISO/IEC 27002. Specific PKI requirements (e.g. certificate content, identity proofing, certificate revocation handling) are not addressed directly by an ISMS such as defined by ISO/IEC 27001^[²⁶^].

The use of an ISMS or equivalent is adapted to the application of PKI service requirements specified in the certificate policy as described in this document.

A PKI trust service provider is a special class of trust service for the use of public key certificates.

This document draws a distinction between PKI systems used in closed, open and contractual environments. This document is intended to facilitate the implementation of operational, baseline controls and practices in a contractual environment. While the focus of this document is on the contractual environment, application of this document to open or closed environments is not specifically precluded.

2 Normative references

3 Terms and definitions

4 Abbreviated terms

5 Public key infrastructure (PKI) general concepts

5.1 General

5.2 What is PKI?

5.3 Use of PKI Service components within example business flows

5.4 Certification authority (CA)

5.5 Business perspectives

5.6 Certificate policy (CP)

5.7 Certification practice statement (CPS)

5.8 Agreements

5.9 Time-stamping

5.10 Trust models

5.11 Component services

5.12 PKI hierarchies and independently managed CAs

5.13 Root CA

6 Certificate policy (CP), certification practice statement (CPS) and their relationship to information security management system (ISMS)

6.1 General

6.2 Certificate policy (CP) guidance

6.3 Certification practice statement (CPS) guidance

7 Certification authority objectives and controls

7.1 General

7.2 Certification practice statement and certificate policy management

7.3 Information security

7.4 Asset classification and management

7.5 Human resources security

7.6 Physical and environmental security

7.7 Operations security

7.8 Access control

7.9 System acquisition development and maintenance

7.10 Business continuity management

7.11 Monitoring, conformance and compliance

7.12 Audit journal security assurance

7.13 CA key life cycle management controls

7.14 Subject key life cycle management controls

7.15 Certificate life cycle management controls

7.16 Root CA controls

7.17 CA certificate life cycle management controls – subordinate CA certificate

Bibliography

BS ISO/IEC 27099:2022

Information technology. Public key infrastructure. Practices and policy framework

Current

Published:

30 Sep 2022