The Research On Proxy Signature Scheme

Information security is the precondition and basis of everything that can work regularly based on the computer network communication. But the information security technology is in low level in our country. We have much work to do in this field.In 1996, Mambo, Usuda and Okamoto first put forward and systemic expound the concept of Proxy signature. Under the original signer and proxy signer's protocol with the force adeffect, the proxy signer can subscribe the files instead of the original signer. Because the proxy signature plays an important role in practical application, it attracts widely attenion when advanced. The domestic and foreign scholars have all taken deeply research to enrich the class of proxy signature and enhance the demand of the security. Various of proxy signature schems emergences.The elliptic curve discrete logarithm problem (ECDLP) is recognized one of the three mathematics difficult problems which can be used to design cryptosystem at present. Since 1997,the public key cryptosystem based on ECDLP has been well studied in international cryptography field. Now the public key cryptosystem based on ECDLP has already turned from the fundamental study stage to the application realization stage, however it is still in starting phase in our country.This subject takes deep research on typical proxy signature and threshold proxy signature at present, and proposes new schemes with identification and safe one-way function mechanism imported, enhance the security and prevent the possible issue, especially to ensure the nonrepudiation.Mainly study as follows:Firstly, this paper sum up the virtue and flaw of the existent kinds of proxy signature schemes and combine the characteristic of the ECDLP and the kownledge of proxy signature, then propose an improved proxy signature scheme without the cooperation of the original signer. Which also analyses and prove the security.Secondly, combine the feature of the threshold and proxy signature, and put forward a threshold proxy signature scheme based on the discrete logarithm cipher mechanism, which needn't the cooperation of the original signer. Which also analyses and prove the security.