HAMMING DISTANCE BASED COMPRESSION TECHNIQUES WITH SECURITY

The proposed algorithm suggests a lossless data compression with security. Input Bit stream is divided into a group of 8-bits each .Encoder deviate the available Randomly generated key according to input bit stream which results into encrypted data. Encrypted key of 64-bits is treated as unit of 4-bits each. Each 4-bits of Key will be at the Hamming distance is of Two from Deviated key. There will be total Six numbers of 4-bits which are at the Hamming distance of Two from Key. These numbers can be indexed by using 3-bits. The index of Three bits of a number is available on the channel as a compressed bit stream. Proposed algorithm is to encrypt the file, compress it, decompress it, and finally decrypt it back to the original file. The algorithm not requires a prior knowledge of data to be compressed. Intelligent algorithm reverse the order of compression & encryption ( i.e. Encryption prior to compression) without compromising compression efficiency , information theoretic security & with lesser computational cost. Proposed algorithm suitable for images, audio as well as text.