A Session Key Based Secure-Bit Encryption Technique (SBET)

In this paper a private key encryption system has been proposed and termed as Secure-Bit Encryption Technique (SBET). A block of stream of bits (b) is taken as input which may be variable. The encryption process is operated on this binary block of size of multiple of 64 bits. A random generated key and a session key (random number generated by the system) are used to encrypt the block through boolean operation where the size and number of blocks is determined by a block-division process. The block is subdivided into left and right sub blocks. The random key also sub divided into two sub groups and expanded separately by padding with zero to make the size of sub block of key equal. The sub block is then XORed with corresponding subdivided key to generate an intermediate block of length b/2 each. The bits are then arranged in two different matrix and read into single matrix which generate the cipher text. The same process may be repeated in a cascade manner for a varying block length which may enhance the security. Decryption is done following the same process as the technique is symmetric. A comparison of the proposed technique with existing and industrially accepted RSA and Triple-DES has also been done in terms of encryption, decryption time; frequency distribution and non homogeneity of source and encrypted files.