The Research And Security Analysis Of Proxy Signature Algorithm

In 1996, Mambo,Usuda and Okamoto first put forward the concept of proxy signature which blazed a new way for the development of digital signature. Proxy signatures has drawn people's attention by its high quality. The research of proxy signature algorithm are studied as follow.(1)First the thesis introduce conception, requirement and categories of proxy signature , and give some typical proxy signature schemes.(2)Through the Cryptanalysis of Gulize et al.'s anonymous proxy signature scheme, it is founded that the scheme is insecure against the forgery attack. Then we analyses a improved scheme, but we also find it insecure that it can't resist public key substitution attack. Finally a secure Anonymous Proxy Signature Scheme is designed; Through the crypyanalysis of a proxy blind signature scheme, it is founded that the scheme is insecure against the proxy signer's linkability attack. Finally, a improved scheme is designed.(3)According to the security analysis of a designated receiver proxy signature scheme, we show that it does not satisfy the security property. On the basis of a designated verifier signature scheme, the paper present a designated verifier proxy multi scheme which satisfy the strong unforgeability and are more efficient. Finally, the higher security designated verifier proxy signature with message recovery based on elliptic curve are designed.(4)Proposes a forward-secure proxy signature scheme with message recovery by updating secret key frequently. When the proxy sugnature secret key is stolen ,the attacker cannot forge the former proxy signature, so we can reduce the loss which caused by the key exposure to a great extent. Considering the characteristics of the elliptic curve cryptosystem, the forward secure designated verifier proxy signature based on elliptic curve is designed.