Overview of digital signature

Two important notion-public key cryptography and one-way trap-door function were introduced,which are related to digital signature,as well as condition which signature schemes should satisfy fully with.Then algorithm and mathematics description of digital signature scheme were presented.Two representative digital signature schemes RSA and DSA were analyzed,so generality and university of mathematics description of digital signature scheme were showed.In the end,two main attacks and four main breaks on digital signature scheme as well as new direction and popular fields of the technology were introduced.