Special Application-oriented Secure Multiparty Computation Protocols

Along with concerning about the issues of information security is growing higher and higher, as the key to ensure data security, cryptography has also been a great deal of development, the application of cryptography today has penetrated into the community in various fields. Secure Multiparty Computation (SMPC) is an extremely general subject, and plays an important role in information security. In multiparty computation, one considers a number of players P_i,i = 1…n, who initially each posses some inputs x_i,i =1…n, and they then want to securely compute some functions f, where f(x₁,…,x_n)=(y₁,…,y_n), after processing, P_i learns y_i but no other information.The SMPC problem is abstract from numerous cryptographic problems, as well as some of the conclusions obtained from the specific issues have guiding significance, it can be said, SMPC is the foundation of cryptographic protocol. As present, the studies of SMPC focus on theory and application.In this paper, we focus on the problem of electronic voting and set operation based on SMPC.1. We have analyzed three types of electronic voting protocols, based on Mix net, based on blind signature and based on multiparty secure sum, and realized the last in network setting. Concerning about some malicious behaviors, we designed an electronic voting protocol based on multiparty secure sum in malicious adversary model which could tracing the traitor when he want to change the voting result. 2. We have analyzed the protocols of set operations based on permutation and polynomial, and proposed a new over-threshold set operation protocol in which the two parties do not know anything about set-intersection but the cardinality of set-intersection over threshold.3. We proposed a privacy-preserving anonymous digital watermarking protocol from the benefit of both seller and buyer in which the seller and the arbiter can trace the illegal distributor without buyer's assistant to resolve the piracy dispute, while the buyer can keep anonymity during the traction unless he is judged by arbiter to be guilty of privacy, so the privacy of seller and buyer are all protected.