Proxy Revocation Mechanism On Proxy Signature And Its Application

As the simulation of handwriting-signature in the network, digital signature can avoidrepudiation, forge and distort in the transmission process of information. In1996, Mambo, etc. putforward the concept of the proxy signature and the proxy signature can realize the delegation ofsigning power in the digital signature. The proxy signer may abuses his/her proxy signing ability, thenthe original signer should revoke the proxy signing ability of proxy signer, so designing a proxysignature with perfect proxy revocation mechanism is of great significance.Firstly, the thesis introduces the development of cryptography, the state-of-art of digital signature,the background of proxy signature. Then we give the research status of proxy revocation andsummarize the disadvantages. We introduce the formal definition, security properties andclassification of the proxy signature. In addition, this thesis also introduces the required mathematicaltheory and some classical proxy signature schemes related to our research contents.Secondly, this thesis analyzes the proxy revocation then put forward a designated-verifier proxysignature scheme with fast proxy revocation. We prove our scheme is secure under random oraclemodel. In our scheme, the original signer can revoke the delegations whenever necessary without athird party by utilizing a time-stamp and a revocation list. Analysis shows our scheme is efficient.Thirdly, this thesis analyzes the security of an existing proxy blind signature and finds somesecurity flaws such as lack of the proxy revocation and the untraceable ability. This thesis put forwarda proxy blind signature scheme with proxy revocation using identity-based cryptosystem. The schemesolves the above flaws and can revoke the proxy signing right without a trusted third party. Theanalysis shows that our scheme has good security and high efficiency.Lastly, this thesis gives the application of proxy blind signature with proxy revocation in theelectronic cash. We give the basic model of the electronic cash based on proxy blind signature. Thenwe put forward an electronic cash scheme based on the proxy blind signature with revocation. In thisscheme the central bank can delegate the issuing right to the branch bank and can also revoke theissuing right of the branch bank when necessarily. The analysis shows that our scheme can satisfy therequirements of anonymity and non-reusable feature and is very significant.