A New Identity-Based Parallel Key-Insulated Signature Scheme without Random Oracles

To allow frequent key-updates without increasing the risk of helper key-exposure, Hanaoka et al. proposed parallel key-insulated mechanism where distinct helpers are independently used in key updates. In this paper, we propose a new identity-based parallel key-insulated signature scheme which is provably secure without resorting to the random oracle methodology. Compared with the known identity-based parallel key-insulated signature (IBPKIS) scheme secure in the standard model, our scheme enjoys more efficient verification.