OT Protocol And Its Application

The concept of OT protocol was first introduced by M.Rabin in 1981, and it has been a fundamental module and primitive knowledge, now. It plays an important part in many cryptographic protocols, such as bit commitment, zero-knowledge proof, secure multiparty computation and the private transaction mechanism of digital productions based on OT protocol is a direct application of OT. However, there is not an article which covers the connotation, extension and application of OT protocol comparatively all-sided at present so as to make it to be a systemic research field and direction. The thesis coordinates and summarizes people's previous achievement, introduced the connotation, extension and application of OT protocol systemically. It depicts and analyzes the meanings, kinds and development course of OT protocol, discusses and analyzes the existing oblivious transfer protocol's design principle and implement, expatiates and proves the relationship between OT protocol and other cryptography fundamental primitives, brings forward the mend idea of private transaction mechanism of digital productions based on OT protocol to make it protect every trade side's behalf better, and then nail down the actual questions which the field's research refer to, thereinto, we make the relationship between OT and primitive PKE be embodied to the relationship between the PKE which are provably secure against IND-CCA2 and malicious OT, we prove that PKE which are provably secure against IND-CCA2 does imply malicious OT. Then, we present an electronic voting scheme based on OT protocol, apply OT protocol to electronic voting for the first time, and it broadens the application of OT protocol. Multi-selection is an important requirement in many actual selection environments, but most previous electronic voting schemes can either just implement "select one in two" or "select one in many" voting or achieve multi-selection with bad security or efficiency, our electronic voting scheme uses the character of OT_n~k protocol to satisfythe requirement that one can at most select k candidates out of n candidates, and solves some questions that exist in FOO electronic voting scheme which is the main frame of many kinds of electronic voting schemes in modern times. The electronic voting scheme based on OT protocol we designed was proved satisfying the basic demand of electronic voting schemes by us, so it's a safe applied electronic voting scheme. Contrast to FOO electronic voting scheme, we analyze the efficiency of our scheme briefly and point out that the scheme can be used in the elections in a largescale. In the end, we summarize the main content and innovation of the thesis, pointout the questions and directions which need us to pay more energy to study in thisfield.