Paper 2026/676

An Efficient Identity-Based Blind Signature Scheme from SM9

Abstract

We present an efficient identity-based blind signature scheme built upon the SM9 Chinese national cryptographic standard. Our scheme achieves weak one-more unforgeability under the $q$-SDH assumption, and computational blindness in the random oracle model (ROM), both proved rigorously. The weak security model, while restricting adversaries from querying signatures on the target identity, remains sufficient for critical applications including electronic cash, anonymous credentials, and privacy-preserving voting systems. We provide rigorous security proofs and demonstrate significant performance improvements over existing SM9-based blind signature schemes, eliminating all online pairing computations through pre-computation. Our construction maintains full compatibility with the SM9 standard, facilitating deployment in certificate-free environments.