A new concurrent signature scheme based on the FAPKC3’s signature scheme

The concept of concurrent signatures was first introduced by Chen, Kudla and Paterson in Eurocryptpsila04, which allows two entities to produce two ambiguous signatures until an extra piece of information (called keystone) is released by one of the parties. Once the keystone is released, both signatures become binding to their true signers concurrently. According to the literatures there are mainly two different methods to realize the concurrent signature schemes. The first one is based on the variants of Schnorrpsilas signature scheme, and the second one is using bilinear pairing. In this paper, we present a new concurrent signature scheme, which is based on the signature scheme of Finite Automaton Public Key Cryptosystem 3 (FAPKC3, for short) which proposed by Renji Tao and Shihua Chen in 1997, and then prove its security under the security model given by Chen et al.. Finally, we briefly discuss our schemepsilas performance.