Research On (t, N) Threshold Scheme Of Cheating Prevention And Its Application

Secret sharing is an important research in cryptography, and (t, n) threshold scheme is a main method to realize secret sharing. In the research of (t, n) threshold scheme, the problem of the participants cheating has not been solved yet, especially how to prevent the last participant or combined participants from cheating. At the same time, (t, n) threshold scheme's application is concerned in recent study.Some secret sharing schemes are discussed and an in-depth research on the problem of the participants cheating in (t, n) threshold scheme is taken in the dissertation. A shadow-exchanged protocol of cheating prevention and a (t, n) threshold scheme of combined participants cheating prevention is proposed. Aiming at the shortages of the internal security in test system, the research on the application of (t, n) threshold scheme of combined participants cheating prevention on test system is taken.The main works and contributions of the dissertation are summarized as follows:Firstly, some classical (t, n) threshold schemes with relevant cryptography knowledge and mathematic knowledge are introduced, then the problem of the participants cheating is analyzed and the relevant research contributions is given in the dissertation.Secondly, base on the in-depth research on the problem of the participants cheating, a shadow-exchanged protocol of cheating prevention is proposed in the dissertation. The problem of the last participant cheating is solved by applying the protocol to the shadow-exchanged stage.Thirdly, a (t, n) threshold scheme of combined participants cheating prevention is proposed in the dissertation. By generationg sub-secret to construct threshold sub-scheme, the problem of combined participants cheating is solved effectively, so (t, n) threshold scheme gets wider future in application.Finally, (t, n) threshold scheme of combined participants cheating prevention are applied to test system. The problem in test system, for example test item -revealed, test time-advanced, are attempted to be solved in the dissertation.