A Quantum-Resistant Self-Sovereign Identity Cross-Domain Authentication System Based on Lattice Cryptography

Abstract

To address centralized trust risks, inadequate privacy protection, and quantum vulnerability of traditional crossdomain authentication systems, this paper proposes a quantumresistant self-sovereign identity (SSI) scheme based on lattice cryptography. Centered on Decentralized Identifiers (DIDs) and Verifiable Credentials (VCs), it constructs a decentralized ecosystem with two key innovations: a “single trapdoor - multi-attribute public key” structure (reducing storage and simplifying key management) and a lattice-based linkable ring signature (balancing anonymity and traceability). Implemented via TrapGen, SamplePre, and rejection sampling, the scheme's security relies on the Short Integer Solution (SIS) problem, with unconditional anonymity and unforgeability proven in the random oracle model. Efficiency comparisons confirm advantages in signature/verification time and storage overhead. This work provides a secure, privacy-preserving post-quantum solution for crossdomain collaboration in smart cities and supply chains. Future work will focus on lattice optimization and zero-knowledge proof integration.