A Galindo-Garcia-Like Identity-Based Signature with Tight Security Reduction
Masayuki Fukumitsu, Shingo Hasegawa · 2017
Galindo and Garcia proposed an identity-based signature based on the Schnorr signature. Although their scheme is proven to be secure in the random oracle model, the security reduction is loose. Later, the security reduction is improved by Chatterjee, Kamath and Kumar, however, the reduction is still loose. In this paper, we propose an identity-based signature scheme which is based on the Schnorr signature. Our scheme follows the idea of the construction of the Galindo and Garcia's one. The security of our scheme is proven to be tightly secure under the DDH assumption in the random oracle model.