Research On Encryption Technique Based On The Interleaved Technique And Modern Cryptography

IT is the important components of the-society production and lives, which including computer technology, communication technology and controlling technology. Information security becomes most important for its secretive, unanimous and undeniable in storage, exchange and usage. To ensure the security of information, in the technique, the general way is through the methods of cryptograph.Cryptography is the core of the information security. Modern cryptograph is divided into the public key system and the private key system. The private key system is also called the single key system, in which the encryption process is the same as the decryption process. The public key system is also called the double key system, where the encryption process is defferent with the decryption process. Since the public key system can publish its public key and keep its private key secret, it has many applications such as the digital signature and authentication, which is widely used in every field of society.Various encryption algorithms have been presented to meet different security technology and application needs. DES, IDEA, SAFER++, AES, RSA and ElGamal, whose security and property have been affirmed continually in their widespread application, are generally established as excellent cryptosystem. They have become the most popular cryptosystems.In this thesis, the basic concepts of cryptogram are introduced. It describes the flow of cryption and decryption of DES algorithm, IDEA algorithm , SAFER++ algorithm , AES algorithm (Rijndael), RSA algorithm and ElGamal algorithm, analyzes the attributes of them. Their security problems are also dicussed.In the communicatins field, interleave technology is used to deal with group errors. The interleaver can break the data sequence, and weaken the pertinence of the data sequence before and after interleaved. So it reduced the harms made by burst errors. The action of breaking the data sequence just can be used for encryption. The interleaving technique is also discussed in the paper, and applied it in data encryption. Proposed applied it in the WORD text encryption algorithm and has carried on with the VB language the realization.This paper further proposes a combined encryption algorithm, which combines interleaving technique and block cipher technology. This algorithm can be used in encryption with OFFICE documents, audio, video, EXE files, etc. It is achieved with VB and MATLAB language.