ISO/IEC 11770-3:2021 PDF

Overview

ISO/IEC 11770-3:2021 - Information security - Key management - Part 3: Mechanisms using asymmetric techniques - defines standardized key management mechanisms that use asymmetric (public‑key) cryptography. The standard covers mechanisms to:

• Establish shared symmetric keys by key agreement (neither party can predetermine the result),
• Transport secret keys (one party chooses a key and securely transfers it to another), and
• Transport public keys in an authenticated (but not secret) manner.

It addresses mechanisms based on finite fields, elliptic curves and bilinear pairings, and includes many concrete mechanism templates and informative examples (including elliptic‑curve examples and pairing‑based examples). The 2021 edition introduces additions such as blinded Diffie‑Hellman mechanisms and an SM9 example.

Key topics and requirements

ISO/IEC 11770-3:2021 focuses on functional and protocol-level mechanisms rather than low‑level transforms. Major technical topics include:

• Key agreement mechanisms (15 variants described, with properties and examples)
• Secret key transport mechanisms (multiple transport mechanisms and examples)
• Public key transport mechanisms (authenticated public key distribution)
• Key derivation functions and examples (used to derive session keys from shared material)
• Cofactor multiplication, key commitment and key confirmation procedures
• A framework for two‑ and three‑party key establishment
• Normative object identifiers and informative annexes with worked examples

The standard explicitly does not cover key lifecycle management, key pair generation/validation processes, or key storage/archival/destruction mechanisms. It also notes that origin authentication can be provided either within a protocol or by using digital signatures.

Practical applications

ISO/IEC 11770-3:2021 is practical for designing, documenting and assessing cryptographic key establishment components of systems such as:

• Secure messaging and VPN protocols
• Transport and session key establishment for TLS-like or custom protocols
• IoT device onboarding and secure provisioning
• PKI and HSM integration where asymmetric techniques bootstrap symmetric session keys
• Secure multi‑party or group key establishment schemes

The standard helps implementers choose and compose well‑understood asymmetric key establishment primitives while ensuring interoperability and consistent security properties.

Who should use this standard

• Cryptographic engineers and protocol designers
• Security architects and system integrators
• Product vendors implementing key establishment (software, devices, HSMs)
• Auditors and compliance teams evaluating key management mechanisms
• Standards bodies and technical writers referencing interoperable mechanisms

Related standards & notes

• Related parts: ISO/IEC 11770 series (Part 1 framework, Part 6 key derivation)
• Cross‑references: ISO/IEC 9798‑3 (authentication mechanisms)
• Security practitioners should note the document’s patent caution and consult the ISO/IEC patent database if required.

Keywords: ISO/IEC 11770-3:2021, key management, asymmetric techniques, key agreement, key transport, public key transport, elliptic curve, Diffie‑Hellman, bilinear pairings.