An electronic cash system based on certificateless group signature

Currently, electronic cash system is one of the most important ways of electronic payment businesses, which requires quick payment and countermeasures against cyber-crime such as falsification of information, double-spending and money-tampering. In this paper, we proposed an efficient elliptic certificateless group signature with forward security and member revocation based on ACJTgroup signature. Compared to ACJT, our scheme has a shorter length of signature with less parameters and only involves a smaller amount of computation, leading to a higher efficiency. We also proposed a fair off-line multi-bank e-cash system based on the newly-proposed group signature scheme. The new e-cash system is considered to have high security and efficiency. And we proved its unforgeability, and prevention against double-spending and money-tampering actions. Our scheme has a significant advantage over the other schemes.