Research On Proxy Signature Schemes

With the rapid development of the computer network technology,when the people enjoy the advantage that taken from the network life,however,the problem of information security is increasingly serious.Digital signature technology is an important content of cryptography,it plays a very important role in the present information society.Because it can ensure the integrity and reliability of the data,and the last it can achieve authenticity.So the digital signature has been widely used in commercial,financial and military fields.With digital signature technology in-depth and practical application,ordinary digital signature schemes cannot be sufficient for the demand of the people,because people often need to delegate some of their powers to a reliable agent in our life,including the right of signature,then the agent can exercise the rights by standing for them.According to this problem,Mambo,Usuda and Okamoto proposed the concept of proxy signature in 1996,and give a way to solve this problem.The proxy signature allows a proxy signer to sign messages on behalf of an original signer,the receiver of the signature verifies the signature itself and the original signer's delegation together.Firstly,this paper introduces the proxy signature's background and significance;secondly,this paper introduces mathematics knowledge on digital signature;thirdly,this paper introduces the basic content of the proxy signature;and then,this paper analyses the paper that is an anonymous proxy signature program proposed by Zhang et al.,and points out the emerging potential risk of their scheme,and then improved their scheme and gives security analysis for the improved scheme;Then,this paper analysis a designated proxy signature scheme and give delegatability attack to it.finally,this paper provides a new proxy signature scheme which can efficiently resist delegatability attack,We also make the security analysis on the new scheme.