Design And Implement Of Information Source Encryption System

With the development of the Internet, the security of computer security is playing an important role .One means of providing security in communications is though encryption. By encrypti6n, data is transformed in a way that it is rendered unrecong-nizable. Only by decryption can this data be recovered. Cryptography offers a set of sophisticated security tools to address the problem of security transaction. Yet, the most common attacks on cryptographic security mechanisms are 'system attacks' where the cryptographic keys are directly exposed, rather than cryptoanalytical attacks (e.g., by analyzing ciphertexts). Unfortunately, such attacks are very common and frequently quite easy to perform, especially since many existing environments and operating systems are insecure (in particular Windows).An scheme based on software encryption combined with hardware encryption Implementation given in this paper is provided to solve the problem mentioned above. Instead encrypt data in PC, it transfer data to "source encryption equipment" via USB connector. After completion encryption/decryption operation, the encrypted data is returned. All encryption/decryption operations are performed in "source encryption equipment", which assure the security of information.The purpose of this paper is to describe the design of a practical implementation of the device mentioned above. This will include the choice and design of the encryption system, the application of DSP in Cryptography, the IDEA algorithm based on FPGA and security of system and. This paper will focus on the basics of cryptography and the implement of cryptographic applications on DSPs.