Research On A Public Key Cryptographic System With Digital Signature

Cryptography has a mazing history. There are many needs in digital information protection and security services,as computer science and information both have been being used ever since1960. Inl976, Diffie and Hellman released a very famous paper, named:New Directions in Cryptography.This can be viewed as an impressive develop ment in Cryptography history.The paper introduced an extremely important concept-Public Key Cryptography and come out with a new way of key exchange.My paper focus on one of Public Key Cryptography-Knapsack Cryptography.Digital Signature is a concept commonly associated with Public Key Cryptography. The concept is a system for the purpose of resititution and verification about information integrity.Encryption simple and clear, decryption fast, at the same time, it does not have to take too much storage space.In practice you can see it is being used everywhere.It seems that Knapsack Cryptography is good, but shamir proved it is not.because there is a good algorithm can break it.Many scholars did a lot of work on it.The main work on Knapsack Cryptography:Find three ways of Encryption and Decryption.One is based on Binary Line Diophantine Equation.The other one out with modular arithmetic in Elementary theory of number.God Another comes from Chinese Remainder Theory.A information unit is being splitted into several parts, and an linear equation is a string of them.Cryptographic system becomes secure and sound,due to the uncertainty solutions of the equation.Based on Complexity theory,1make some analysis on the security of Cryptographic system. Information will be inevitably lost or changed.There is a need to recover the broken information.Digital Signature can solve this.The main work on Digital Signature:Information Encryption Base on RSA Digital Signature system.