An Efficient Signcryption Schemes Based on Bilinear Maps

Unforgeability is a primitive property of a secure digital signature. As an extensions of digital signature, signcryption plays an important role in the sensitive transmission. Since it can fulfill both the functions of digital signature and public key encryption simultaneously, at a cost significantly lower than that required by the traditional signature- then- encryption approach. In the work, we proposed an efficient signcrypiton scheme based on bilinear maps. Our proposed scheme satisfies the semantic security, unforgeability, and public authenticity. We also give the formal security proof in the random oracle model, and the security of the scheme is related to the CDH problem.