An Identity-Based Blind Signature Scheme with Message Recovery from Pairings.

As a variant of digital signature schemes, the blind signature enables that the signer signs a message without knowing its content. In identity-based cryptography, many blind signature schemes have been proposed. Among them, Verma et al. designed an identity-based blind signature scheme with message recovery (IDBS-MR). Unfortunately, after our cryptanalysis, their scheme cannot satisfy untraceability, which enables the signer to break the anonymity of users by tracking the previous signature transmission scripts. To solve the problem, we construct a new IDBS-MR scheme using the bilinear pairing and demonstrates that the proposed scheme has blindness, untraceability, and unforgeability in the random oracle model. Performance results show that compared with Verma et al.’s scheme, the proposed scheme has the same computation costs in views of signers, twice computation costs in views of users, but reduces 36% computation costs in views of verifiers.