Research On Strong Designatured Verifier Signature Schemes

With the development of networks technology and the wide application of information technology, the information security has become a very important issue in today. The digital signature, as one of the crucial components of cryptography, is playing an important role in protecting the security of communication networks.In practical application, there are various types of digital signatures, which can be used to satisfy various security requests.In this paper, one specific digital signature---strong designated verifier digital signature and its application were studied. The main achievements contained in this thesis are as follows:(1) The flaws that exist in some existent designated verifier signature schemes are analysed. Typical attack such as deligatability attack is discussed, in which the signer can delegate his(her) sign ability to fixed designated verifier or any third party without disclosing his (her) secret. thereby, any third party created the signature was accepted designated verifier.(2) Two typical strong designated verifier proxy signature schemes are analysed. Based on their schemes,two new designated verifier proxy signature schemes are proposed. Compared with SV's scheme, Scheme I has a lower computional cost; Scheme II is proposed based on Wang's scheme, which not only has shorter signature length, but also has lower computional cost and more applicable in the networks with low bandwidth.