Proxy Signature And The Research Of Its Applications

Together with the rapid development of network, electronic commercial affairs and electronic government affairs are going into people's actual lives, and digital signatures have wide application. But in actual lives, sometimes people want to entrust their singing power to reliable attorney and let him to exercise signing power. In today of electronic information, the problem of proxy signature also appears.The concept of proxy signature was proposed for the first time by Mambo, Usuda and Okamoto in 1996. Proxy signature is that original signer entrust his signing power to appointed attorney to exercise signing power standing for original singer. Proxy signature has important application in many fields such as mobile agents, electronic cash, electronic election, electronic auction etc. According to different application environments, all kinds of proxy signatures having different function were proposed, such as proxy blind signature, blind proxy signature, threshold proxy signature, nomination proxy signature etc.In view of the intrinsic proxy signature schemes, in this paper, some proxy signature schemes and their applications are researched. The main contributions are as follows:(1)Through the cryptanalysis of Lu et al.'s certificateless proxy signature schemes, we show that the scheme can't resist forge attack of the two kinds of attackers in certificateless public key code system. Aiming at the safe problem, an improved certificateless proxy signature scheme proposed in this paper, which ca n increase the safety and credibility.(2)By the cryptanalysis of Huang et al.'s high effective threshold proxy signature scheme, finding the scheme can't effectively resist forge attack and public key exchange attack. Based on the above security problem, we gave an improved scheme taking advantage of the zero-knowledge proof. And its security is based on Schnorr Signature scheme and the Problem of Discrete Logarithm.(3) Using ECC and zero-knowledge proof, a blind proxy blind signature scheme based on the Elliptic Curve was proposed, which has small amount of computing, the quality of high security and high efficiency of implementation. And the scheme satisfies the security properties of both the blind proxy signature and the proxy blind signature scheme.(4)Using of the security of threshold scheme, a shared verification proxy signature scheme with message recovery was proposed. This scheme needn't deliver the message with signature, which can reduce the communication cost and the risk of verifier deception.(5)Applying proxy signature scheme based on the Elliptic Curve, we gave a new scheme of electronic cash, and point out that proxy blind signature scheme has good application value.