Design And Analysis Of Multi-threshold Group Signature Scheme

The research of this thesis focuses on threshold group-signature. Firstly the thesis introduces some basic concepts and tools which used by other parts, then summarizes eight principles of threshold group-signature, and analyses six schemes of threshold group- signature. The analysis shows these schemes all have some defects. So a problem, how to design a good scheme of threshold group-signature, is expounded.At the beginning, the thesis observes an application and defines a new concept, multi-threshold group-signature. There are eight principles of multi-threshold group-signature too. Then the thesis designs a scheme with creditable center, which is based on discrete logarithm and Lagrange formula. The thesis also analyses the security of the scheme.For a scheme of multi-threshold group-signature includes a scheme of threshold group-signature, the scheme expounded in the thesis also gives a good answer to the problem above.