Overview
ISO/IEC 20008-1:2013 - Information technology - Security techniques - Anonymous digital signatures - Part 1: General defines the principles, models and general requirements for anonymous digital signature mechanisms. It covers two broad categories: mechanisms using a group public key (group signatures) and mechanisms using multiple public keys (ring signatures). The standard establishes a common vocabulary, entity roles, processes (key generation, signing, verification) and high-level security requirements for anonymity and verifiability.
Key Topics
- General model and entities: group, group member, group membership issuer, evidence evaluator, verifier, etc.
- Core processes: key generation, group membership issuing, signature creation, signature verification.
- Specialized processes for group signatures: group membership opening (to reveal signer under authorised conditions), signature linking, and revocation procedures.
- Anonymity strength: defined as the probability measure that an unauthorised party can correctly identify the signer (e.g., anonymity strength n means probability 1/n).
- Revocation levels for group public-key mechanisms:
- revoke an entire group,
- revoke a specific member’s membership,
- revoke authorization for a member to create specific signature types.
- Evidence of binding and evidence evaluation: mechanisms to produce and check data that ties a signature to a signer for authorised parties while preserving anonymity against unauthorised observers.
- Security foundations: reliance on well-known intractability assumptions (factorization, discrete logarithm) and use of standard crypto primitives such as collision-resistant hash functions and conventional signature/encryption mechanisms where required.
Applications and Who Uses It
ISO/IEC 20008-1:2013 is aimed at organizations and professionals building privacy-preserving authentication and signing systems:
- Security architects and cryptographic engineers designing anonymous authentication, e-voting, privacy-preserving audit logs, and anonymous credential systems.
- PKI operators and membership authorities managing group issuance, revocation and policy enforcement.
- Protocol designers and software vendors who implement group/ring signature schemes or integrate them into messaging, identity and blockchain solutions.
- Standards bodies and compliance teams aligning implementations with international security requirements.
Benefits include standardized terminology, clear process models for group-based anonymity, and guidance on controlled de-anonymization and revocation.
Related Standards
This part provides the foundational framework for implementing anonymous digital signatures in information technology security solutions.