Toward Tight Security of the Galindo–Garcia Identity-based Signature

Galindo–Garcia identity-based signature (GG IBS) is an efficient (IBS) whose security proven under the discrete logarithm (DL) assumption. Since original reduction of GG IBS loose, there are some works to improve factor. However, such improvements do not achieve tight sufficiently, or efficiency resulting scheme much worse than scheme. In this paper, we propose a new improvement IBS. The proposed has from decisional Diffie–Hellman (DDH) assumption with respect model which weaker that Our better previous also DDH