A New Blind Identity-Based Signature Scheme with Message Recovery

In this paper, a new blind identity-based signature scheme with message recovery based on bilinear pairings on elliptic curves is presented. The work is motivated by the importance of blind signatures as a cryptographic primitive essential in protocols that guarantee anonymity of users. This is particularly of interest in DRM systems, electronic cash systems, electronic voting systems and location-based mobile services that are becoming common those days. Anonymous identifiers may be used to protect the privacy of users. Blind signatures present a practical tool for issuing such identifiers. The proposed scheme is a blind signature scheme with message recovery and consequently achieves bandwidth savings. Since the proposed scheme is identity-based, the user’s public key is easily extracted from his identification information. This eliminates the certificates for public keys needed in traditional public key cryptosystems. Moreover, the use of bilinear pairings over elliptic curves enables utilizing smaller key sizes, while achieving the same level of security compared to other schemes not utilizing elliptic curves. The correctness of the proposed scheme has been validated. Security proofs for the blindness property and unforgeability have been developed.