Group Signature And Application

In the times of network, the information security is getting more and more important, as an important branch of digital signature, group signature has broad prospect in the application of the information security. To find a secure group signature scheme with high efficiency and apply it to the security management of document, the paper analyzes several group signature schemes, including the group signature schemes which are constructed with signature of knowledge and the schemes which are based on Chinese remainder theorem. In this process, the paper firstly analyzes security problems of member join in several schemes and brings forth the method to solve the problems. After then, the paper analyzes a secure group signature scheme shared among different groups and proves that the scheme can not resist the forgery attack.By comparing the efficiency of those schemes, the RSA system which can be easily applied is chosen as the base of realization. After analyzing the security and efficiency limitation of those group signature schemes based on Chinese remainder theorem, the paper proposes a new scheme based on Chinese remainder theorem. The new scheme is securer and more efficient. Furthermore, every operation in the scheme is simple and easy. So it provides a realization foundation of the document security management system.For the realization of new group signature scheme, the paper analyzes the various algorithms in detail. By summarizing the researches that have been done, a set of methods of programming is presented.Finally, a document security management system based on the new group signature scheme is constructed. According to the characteristic of the system, certain modifications are done to the new scheme to adapt efficiency request of the system. After it, the paper brings forward the methods to realize the system.