Two Threshold Multisignature Schemes from Bilinear Pairings

Threshold multisignature combines the traits of threshold signature and multisignature. It solves the problem that any t users can impersonate other t users´ signatures in threshold signature. Identity-based public key systems allow the user to use his identity as the public key, which can simplify the key management procedure compared with CA-based public key systems. In this paper, we propose two threshold multisignature schemes from bilinear pairings. One is based on CA and another is based on identity. Both of them can solve the problem that any t users can impersonate other t users´ signatures. The former has shorter signatures but needs a CA to issue certificates. In contrast, the latter doesn´t need a CA to issue certificates.