Digital Signatures: Status and Challenge

Digital signature is a central cryptographic primitive. Since the standard definition on the security of signature schemes is given in the paper, there have been many attempts to design practical and provably secure signature schemes in this security model. Different assumptions and tools have been used in these constructions. In this paper, the authors give a survey on these signature schemes and show the status and challenge in signatures. In cryptography, one of the breakthroughs is the proposal of public key cryptosystem. It can not only be used for encryption, but also can be used in authentication and undeniability.