Soa problem, how to design a good scheme of threshold group-signature, is expounded. At the beginning, the thesis observes an application and defines anew concept, multi-threshold group-signature. There are eightprinciples of multi-threshold group-signature too.
Then the thesisdesigns a scheme with creditable center, which is based on discretelogarithm and Lagrange formula. The thesis also analyses thesecurity of the scheme. For a scheme of multi-threshold group-signature includes ascheme of threshold group-signature, the scheme expounded in thethesis also gives a good answer to the problem above.