International Journal of Computer Science and Communication Security (IJCSCS)
MARS is a shared-key (symmetric) block cipher supporting 128-bit blocks and variable key size. MARS is designed to take advantage of the powerful operations supported in today's computers, resulting in a much improved security/performance tradeoff over existing ciphers. In this paper a metamorphic function is added to the MARS cipher that now can be called metamorphic-enhanced MARS. This function uses XOR, ROT, INV and NOP logical operation to improve the ciphering process. This paper enhancement is to make a high confusion without disturbing the linear and differential characteristics of the MARS cipher.