Multilevel security and compression of text data using bit stuffing and huffman coding

Data security and compression is the common requirement for most of the storage and transmission related applications. In this paper, a new method for multilevel security and compression of text data using bit stuffing and Huffman coding is presented. The proposed method comprises various processing modules for securing and compressing the text data through encryption process. The encryption process involves three phases to encrypt the data. In the first phase, the bits of every eighth character in the text will be embedded in the most significant bit positions of preceding seven characters. This process creates an encrypted text data which will be further processed for second level encryption. During second phase, every character of encrypted text is XORed with secret key provided by the sender that authenticates the sender. In the third phase, final encryption is done using Huffman encoding method. In decryption process, the ciphertext passes through three phases to reconstruct the original text. The encrypted data is decrypted using Huffman decoding method in the first phase. Then, the decrypted data and secret key that authenticates the receiver are used to reconstruct the original text in the last two phases of decryption process. Hence, the method provides multistage security for text data and also compresses the text data to larger extent. The results obtained are highly encouraging and the system is very effective in providing high level security and higher shrinkage or reduction of memory that result in reduction of bandwidth and transmission time. An average percentage of shrinkage or reduction of memory is 45.41%.