Lattice‐Based Fault Attack and Defensive Strategies Targeting the SM2 Signature Algorithm

ABSTRACT Fault attacks targeting signature nonce pose a critical threat to elliptic curve digital signatures, potentially exposing private keys through non‐invasive methods. This letter presents an efficient and practical defence strategy against lattice‐based fault injection attacks on ephemeral nonce in the SM2 digital signature algorithm (SM2‐DSA). Our proposed countermeasure effectively protects against such sophisticated lattice‐based fault attacks while maintaining minimal overhead in both time and hardware resources. Specifically, our countermeasure incurs only a 0.8% time overhead and the area overhead for secure design does not exceed 1%. Our research provides valuable insights for evaluating the security of hardware implementations of SM2‐DSA.