Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
BS ISO IEC 11770 — Information Technology — Security Techniques — Key Management Series
Information Technology — Security Techniques — Key Management (2006–2016 edition family)
🔐 BS ISO/IEC 11770 is the British Standard family published by BSI adopting the ISO/IEC 11770 series on information technology security techniques — key management. The series comprises six documents and was developed with participation from BSI Technical Committee IST/33 (IT security techniques). It provides an internationally harmonized framework and concrete mechanisms for the key lifecycle — generation, distribution, use, update and revocation: Part 1 gives the overall framework; Parts 2 and 3 specify key-establishment mechanisms using symmetric and asymmetric techniques respectively; Part 4 deals with mechanisms based on weak secrets; and Parts 5 and 6 address group key management and key management services. The series is a foundational standard family for modern cryptographic engineering, communication security, financial payment and identity-authentication security design.
💡 Some parts of this series are archived as scanned images; the related technical content in this article is compiled from public-domain knowledge. Always verify against the current BSI edition before citing.
1. Series Overview and Positioning 📌
The security strength of any symmetric cipher or authentication protocol ultimately depends on the security of the keys. Key management covers every operation in the key lifecycle: key generation (true random source, length and entropy), key distribution/establishment (point-to-point negotiation or via a key distribution centre), key storage and backup, key lifetime and update, and key revocation and destruction. The value of the ISO/IEC 11770 series is that it systematizes and normalizes the key-establishment protocols scattered throughout the cryptographic literature, and formally states the security objectives and properties (confidentiality, integrity, forward secrecy, etc.) of each mechanism, providing a unified benchmark for evaluating key-management schemes. BS ISO/IEC 11770 is the official UK implementation of that series.
⚠️ The choice of key-management mechanism must match the security objectives of its application environment: high-risk environments should use mechanisms that provide forward secrecy and mutual authentication; mechanisms based solely on weak secrets (weak passwords) are suitable only for specific constrained scenarios and need protective measures such as limited retries.
2. Series Structure and Technical Content 📚
The six documents of the BS ISO/IEC 11770 series (of varying edition years) form a complete key-management system:
| Part | Subject | Main Content | Year |
|---|---|---|---|
| BS ISO IEC 11770-1 | Framework | Overall framework, conceptual model and terminology of key management | 2010 |
| BS ISO IEC 11770-2 | Mechanisms using symmetric techniques | Point-to-point key establishment and symmetric mechanisms via a key distribution centre | 2008 |
| BS ISO IEC 11770-3 | Mechanisms using asymmetric techniques | Public-key key-establishment/wrapping mechanisms and key derivation | 2015 |
| BS ISO IEC 11770-4 | Mechanisms based on weak secrets | Key-establishment mechanisms based on weak secrets such as passwords (scanned, from public-domain knowledge) | 2006 |
| BS ISO IEC 11770-5 | Group key management | Group key establishment and management mechanisms (scanned, from public-domain knowledge) | 2011 |
| BS ISO IEC 11770-6 | Key management services | Key-management service interfaces and trust relationships (scanned, from public-domain knowledge) | 2016 |
The internal logic of the series: Part 1 establishes the framework and model; Parts 2 and 3 cover the two main technical routes — symmetric and asymmetric — and are the core mechanism specifications; Part 4 addresses weak-secret scenarios such as passwords; Parts 5 and 6 address group and service systems. In engineering, the appropriate part is selected by application environment (point-to-point, client-server, group, cloud service).
✅ Parts 1 to 3 of the series are available as full readable text; Parts 4 to 6 are scanned versions and are summarized here on the basis of general knowledge in the field.
3. Key Technical Requirements 🔬
3.1 Framework (Part 1)
Part 1 establishes the conceptual framework of key management: it defines key types (secret keys, private/public key pairs), key hierarchy (master keys, session keys), entity roles (initiator, responder, key distribution centre, key management centre) and lifecycle stages. The part harmonizes the terminology and the description of security properties, and is the basis for understanding all subsequent mechanisms. It also specifies the representation of key attributes (such as key usage, algorithm identifier and validity period).
3.2 Mechanisms using symmetric techniques (Part 2)
Part 2 specifies various mechanisms for establishing keys using symmetric cryptographic techniques: both point-to-point key establishment between two entities using a pre-shared secret (e.g., key wrapping, key transport) and establishment assisted by a trusted key distribution centre (KDC). Each mechanism defines the protocol message flow, key-derivation steps, integrity protection and security preconditions. Typical applications include the underlying mechanisms of Kerberos-like protocols and financial cryptographic infrastructures.
3.3 Mechanisms using asymmetric techniques (Part 3)
Part 3 specifies mechanisms for establishing keys using public-key cryptography, including: key transport (encrypting a session key with the recipient’s public key), key agreement (e.g., DH-type protocols), key encapsulation (KEM), and key derivation functions (KDF) that derive keys from a shared secret. The part systematically describes the encoding, length and security parameters of keys, and the security properties provided by each mechanism (mutual authentication, forward secrecy, key confirmation), serving as the base reference for the key-establishment portions of TLS/SSH-type protocols.
⚠️ The security of any mechanism depends on correct parameter implementation: random-source quality, key length, elliptic-curve/group parameter selection, and salt and context separation in the derivation function. A small implementation deviation (e.g., not validating public keys) can lead to severe vulnerabilities.
4. Engineering Practice 🛠️
- 🔍 Protocol design: select key-establishment mechanisms that meet the security objectives of communication and authentication protocols, and manage random numbers and the key lifecycle explicitly.
- 🔧 Key management infrastructure (KMS): organize the key hierarchy, backup and access-control policies in hardware security modules (HSM) according to the framework.
- 📊 Compliance and evaluation: evaluate the mechanism selection and security attributes of third-party key-management schemes against this series, supporting security audits and compliance arguments.
- 📋 Key rotation and revocation: define update cycles, leak response and revocation procedures based on mechanism attributes, and incorporate them into operational management.
5. Frequently Asked Questions ❓
❓ Q: What is the difference between key establishment and key distribution?
A: Key establishment means two or more entities jointly produce or obtain a session key through a protocol; key distribution usually means a trusted third party (a key distribution centre) securely sends a key to the entities — it is one implementation route of establishment.
A: Key establishment means two or more entities jointly produce or obtain a session key through a protocol; key distribution usually means a trusted third party (a key distribution centre) securely sends a key to the entities — it is one implementation route of establishment.
❓ Q: Why must weak-secret (password) mechanisms be treated with particular care?
A: Password space is small and vulnerable to offline dictionary attacks; mechanisms based on weak secrets must converge the attack surface through strict rate limiting, delay and (where necessary) online entropy increase, and typically cannot provide forward secrecy.
A: Password space is small and vulnerable to offline dictionary attacks; mechanisms based on weak secrets must converge the attack surface through strict rate limiting, delay and (where necessary) online entropy increase, and typically cannot provide forward secrecy.
🔍 Q: Why are Parts 4 to 6 marked as “scanned”?
A: In this batch of archive material, those parts exist as scanned images; the technical content is summarized from public-domain knowledge. Verify against the current BSI edition before formal citation.
A: In this batch of archive material, those parts exist as scanned images; the technical content is summarized from public-domain knowledge. Verify against the current BSI edition before formal citation.
❓ Q: How does this series relate to protocol standards such as TLS and FIPS?
A: This series defines the cryptographic mechanism layer; protocols such as TLS/SSH and implementation guides such as NIST SP 800-56 specify the concrete message ordering and formats above this layer — the two complement each other.
A: This series defines the cryptographic mechanism layer; protocols such as TLS/SSH and implementation guides such as NIST SP 800-56 specify the concrete message ordering and formats above this layer — the two complement each other.