ISO IEC 11770-5-2020 PDF

Full title and description

ISO/IEC 11770-5:2020 — Information security — Key management — Part 5: Group key management. This international standard specifies mechanisms for establishing shared symmetric keys within groups of entities, including KDC-based mechanisms, tree-based logical key structures and key-chain approaches that support group forward and/or backward secrecy.

Abstract

This document defines symmetric key-based key establishment mechanisms for multiple entities using a key distribution centre (KDC), tree-based logical key structures with individual and batch rekeying, and key-chain mechanisms that provide group forward secrecy, group backward secrecy, or both. It describes the required contents of messages that carry keying material or establish conditions for keying material exchange, while excluding explicit message formats, initial secret provisioning methods and key lifecycle management.

General information

• Status: Published.
• Publication date: 10 November 2020 (Edition 2, 2020).
• Publisher: International Organization for Standardization (ISO) / IEC (JTC 1/SC 27).
• ICS / categories: 35.030 (IT security).
• Edition / version: Edition 2 (2020).
• Number of pages: 18 pages.

Scope

Specifies mechanisms to establish shared symmetric keys among groups of entities. The standard covers KDC-based symmetric key distribution for multiple entities, tree-based logical key structures (supporting both individual and batch rekeying), and key-chain approaches that achieve various forms of group secrecy (forward, backward or both). It describes required message content for keying operations but does not mandate explicit message formats, initial secret provisioning methods between entities and a KDC, lifecycle management of keys, or interdomain key management.

Key topics and requirements

• Group key establishment mechanisms for symmetric keys (KDC-based approaches).
• Tree-based logical key structures supporting individual rekeying and batch rekeying.
• Key-chain based mechanisms providing group forward secrecy, group backward secrecy, or both.
• Definition of required content for messages that carry keying material or set conditions for establishment.
• Explicit message formats, initial key provisioning between entities and KDC, key lifecycle management and interdomain key management are outside the scope.

Typical use and users

Used by security architects, protocol designers, cryptographic library authors, system integrators and implementers of secure group communication (for example multicast, conferencing, collaborative platforms, IoT and smart-city systems). Organizations designing or evaluating group key management components for secure messaging, content distribution or group services will consult this part of ISO/IEC 11770. The standard is maintained by ISO/IEC JTC 1/SC 27 and is referenced in contexts such as cybersecurity and smart-city deployments.

Related standards

ISO/IEC 11770 is a multipart series on key management. Key related parts include: Part 1 — Framework (ISO/IEC 11770-1:2010); Part 2 — Mechanisms using symmetric techniques (ISO/IEC 11770-2:2018); Part 3 — Mechanisms using asymmetric techniques (ISO/IEC 11770-3:2021); Part 4 — Mechanisms based on weak secrets (ISO/IEC 11770-4:2017); Part 6 — Key derivation (ISO/IEC 11770-6:2016). Implementers often consult these parts together when specifying end-to-end key management and related cryptographic operations.

Keywords

Group key management, key distribution centre (KDC), logical key tree, rekeying, key chain, forward secrecy, backward secrecy, symmetric key establishment, keying material, ISO/IEC JTC 1/SC 27, IT security (ICS 35.030).

FAQ

Q: What is this standard?

A: ISO/IEC 11770-5:2020 is Part 5 of the ISO/IEC 11770 series and defines group key management mechanisms for establishing shared symmetric keys among multiple entities. It is an international standard published in November 2020.

Q: What does it cover?

A: It covers KDC-based symmetric key establishment for groups, tree-based logical key structures with individual and batch rekeying, and key-chain mechanisms that provide group forward and/or backward secrecy. It specifies the required contents of keying messages but does not define exact message formats, initial secret provisioning or key lifecycle management.

Q: Who typically uses it?

A: Security architects, protocol designers, cryptographic implementers, system integrators and organizations building secure group communication (multicast, conferencing, collaborative services, IoT/smart-city deployments) use this standard as guidance for group key management design and evaluation.

Q: Is it current or superseded?

A: ISO/IEC 11770-5:2020 (Edition 2) is the current published edition that superseded ISO/IEC 11770-5:2011. The standard is subject to the regular ISO review cycle.

Q: Is it part of a series?

A: Yes — it is Part 5 of the ISO/IEC 11770 series on key management. Other parts cover the framework (Part 1), symmetric techniques (Part 2), asymmetric techniques (Part 3), weak-secret mechanisms (Part 4) and key derivation (Part 6).

Q: What are the key keywords?

A: Group key management, KDC, logical key tree, rekeying, forward secrecy, backward secrecy, symmetric key establishment, keying messages, ISO/IEC JTC 1/SC 27.