Digital signatures: A survey of undeniable signatures

Digital commercial transactions are so important to us these days that authentication just cannot be overlooked or ignored in a secure cryptographic system. This thesis gives a survey of a few modern authentication schemes. It pays special attention to Undeniable Signature Schemes and their applications. It is believed that Undeniable Signatures have a great potential to be applied to the real world of practical electronic commercial transactions because they protect the interests of both signer and verifier. A form of Undeniable Signatures is implemented in the process of understanding the scheme and the mechanism of the technique.