Research On Designated Verifier Signatures And Chameleon Signatures

Digital signature, as one of the most primary methods of protecting information security, has become a new important subject in the information security. The focus of this thesis is analyzing the designated verifier signatures and its appliances, a new designated verifier signatures scheme is presented; at the same time, Chameleon signatures are elementarily researched and a promoved scheme is presented. The main contributions are as follows.1. As there is some objection about the security attestation of the scheme proposed by Willy Susilo, etc., another method to attest is given in this paper. Based on the new attestation, an ID-based strong designated verifier signature scheme with message recovery is proposed which adapts for signing short message with high harmony requirement of privacy and authentication and limited bandwidth.2. Chameleon signature is based on traditional hash and sign paradigm, but what makes it differ from the ordinary signatures is the hash function it used--Chameleon hash. A secure chameleon scheme provides the properties of non-interaction, non-transferability and non-repudiation. A new ID-based Chameleon signature scheme is proposed in this paper which is based on the bilinear pairings. It's secure under Random Oracle.