Research On Related Theories And Application Of Subliminal Channel

With the rapid development of networking information technology and computer technology, information hiding which is an old and young subject in information security has made a stride in theories and technology. Information hiding integrates a large number of research results of cryptography, information theory, modern algebra, digital image processing, computer security, management science, psychology, economics, law and related subjects. Subliminal channel which is a typical modern hidding information technology become a hot research subject and has broad applications, such as in military intelligence, privacy, security and currency watermark. The subliminal channel is a covert channel, which is uesed to send a additional secret message to an authorized receiver, the message can't be discovered by any unauthorized receivers.The channel is constructed on cryptosystems such as digital signature, authentication and so on. In this dissertation, we mainly discuss the designing methods of subliminal channel, as well as the applications of subliminal channel in several fields.In this dissertation, we reviewed the research work and the current development of information hiding and the subliminal channel. We introduce the basic contents such as digital signature, ElGamal algorithm, the specified receiver signature encryption scheme and its improved shceme, vector space secret sharing scheme, conic curve over Z n and digital signature based on conic curve over Z n, etc. Then we intoduced the designing principles of subliminal channels, and proposed several subliminal channels scheme. Finally, we discuss the application of subliminal channel in anonymous proxy signature, the group signature , key exchange algorithm and law-hidding of S-rough sets.The research results of this dissertation are summarized as follows:1) This dissertation improved the specified receiver signature encryption scheme by the Cao Zhen-fu, so that it can be used to fulfill the subliminal channel;2) This dissertation proposed two subliminal channel schemes respectively based on the Lagrange polynomial interpolation and the Chinese Remainder Theorem. In these schemes, the subliminal message is divided into several irrelevant subset message, the numerical simulation of these schemes were provided. 3) This dissertation proposed a subliminal channel based on vector space secret sharing scheme and the improved specified receiver signature encryption scheme.The concept of threshold multi-subliminal channel was proposed, and a scheme based on Lagrange interpolation polynomial and the improved specified receiver signature encryption scheme;4) This dissertation proposed a anonymous proxy signature scheme based on the conic curve over Z n and a group signature scheme based on orthogonal vectors. The subliminal channel was applied to reveal the true signer in the two signatures when necessary;5) The dissertation used the subliminal channel to improve the algorithm. The improved algorithm can effectively resist the middle man attack and had the advantages of the original algorithm;6) This dissertation proposed two schemes of the hiding and authentication of function S-rough sets laws based on subliminal channel, one is a non-threshold scheme and another is a threshold scheme. These schemes can simultaneously provide hiding and certification for the value of the law properties sets.