Research On Proxy Digital Signature Schemes

Proxy digital signature has a universal application in real life. Unforgeability and non-repudiation is important nature for proxy signature. But most of proxy digital signature schemes have not it now, Simultaneously, How solves secure channel problem between an original signer and a proxy signer and signature efficiency problem is further studied preparaly .This article discusses proxy signature schemes. The main contents that the author obtained are as follows: First, we introduce basic digital signature schemes and digital signature schemes'various attack. in Random Oracle Model, we prove schnorr signature is secure for adaptive chosen message attack;Secondly ,we introduce basic proxy signature schemes. Using the elliptic curve Cryptosystem which is secure and high efficient, we respectively propose a new proxy signature scheme and a new proxy multi-signature scheme of security and high efficiency, which have not secure channel; Thirdly ,we analyse security of Lee et al.'s undesignated proxy signature and Shum et al.'s proxy signature scheme with proxy signer privacy protection, conclude that Shum et al's scheme has not strong unforgeability, and propose a modified strong proxy signature scheme with proxy signer privacy protection, which has secure analysis; Last, we analyse and study security of Dai et al.'s designated confirmer proxy signature and Wang's weak designated confirmer proxy signature and strong confirmer proxy signature scheme.Combining elliptic curve and designated confirmer proxy signature, we respectively propose a new designated confirmer proxy signature scheme and a new designated confirmer proxy multi-signature scheme based on elliptic curve discrete logarithm problem ,which have secure analysis.