A Modular Zero-Knowledge Credential Framework for Multi-System Attribute Verification with Scoped Unlinkability and Efficient Accumulator-Based Revocation

Abstract

This paper presents a zero-knowledge credential framework for secure and privacy-preserving attribute verification across multiple independent systems. The framework enables users to prove statements about their attributes without revealing the underlying values, while preventing cross-domain tracking by eliminating globally stable identifiers. The construction combines commitment schemes, digital signatures, zero-knowledge proofs, scoped pseudonyms, and accumulator-based revocation into a unified and modular design. Scoped identifiers ensure that user activity cannot be linked across different verification domains, while predicate proofs allow verification of conditions such as threshold checks without disclosing sensitive data. Revocation is supported through an efficient accumulator mechanism that enables verification without revealing credential identities and without increasing cost with the size of the revoked set. The system follows a complete lifecycle including credential issuance, proof generation, verification, and revocation checking. All proofs are non-interactive and bound to verifier-specific challenges, ensuring resistance to replay attacks. Security is based on standard cryptographic assumptions, providing guarantees for attribute privacy, proof soundness, unlinkability, and resistance to collusion. Experimental evaluation demonstrates that the framework achieves practical performance, with low verification latency, compact proof size, and stable scalability. The results show that strong privacy, verifiable authenticity, and efficient revocation can be achieved simultaneously without relying on trusted setup or pairing-based cryptography. The modular structure further supports integration with decentralized identity systems and real-world deployment scenarios.