The Study Of Stream Cipher Based On The Petri Net

With the rapid development and wide application of communication and network technology, more and more information has been transmitted through the network. Therefore, the information security and protection are getting more and more important. which makes cryptography theory technology become an important research field in information science and technology. The stream cipher is one of the important branches of modern cryptography. Its birth and development have a wide range of practical background and important theoretical value.Because of its simple password fast, encryption speed and the error in ciphertext transmisson will not express in the plaintext. The stream cipher still maintains advantage in practical application, particularly in the special and confidential agency. Recently with the develepment of shift register theory and together with the effective mathematical tools,the stream cipher theory has made great progress.The current generator design of the stream cipher sequence was done mainly by using a linear feedback shift register to generate pseudo-random sequence. In recent years plenty of stream cipher system has been produced,such as using chaos theory to produce pseudo-random sequence .The block cipher based on the Petri net by Professor Wu Zhehui is an encryption method with division of variable length.The network run by Petri net for the 2~k replacement to determine the block cipher whose length is k .Based on it Wu Zhenhuan used the unbounded Petri net with unique reachable vector to operate a key sequence and presented encryption scheme based on the Petri net. This article has studied the scheme of stream cipher based on the Petri net, the paper structure is as follows:1 Introduce the basis knowledge of cryptology and the current research situation of the steam cipher;2 Focus on the shift register cipher and several common structure based on the key generator sequence, analyze and study the ;stream cipher;3 Introduce the basis knowledge of the block cipher based on the Petri net,and analyze it;4 Present the non-linear generator based on the Petri net and conducted a preliminary study, combining the characteristics of non-linear sequence of portfolio based on the Petri net flow of encrypted password system on the basis of improvement...