International Journal of Engineering and Technology

This paper describes about novel key expansion and its inversion technique for private key cryptosystems. Our design uses (8, 4) Extended Hamming Code and its error control logic to produce memory efficient key schedule generation algorithm. A mathematical relationship between 4bit word and its corresponding 4bit parity bits is shown. Simplicity, symmetry elimination, diffusion and non-linearity of the proposed key expansion technique are described as the key schedule generation criteria. Proposed method removes the usage of S-box to reduce the working memory of the algorithm. High nonlinearity penetration of original input message bits is achieved by applying modulo2 addition of code based key schedules for each round transformations. Security strength among these key schedules is achieved by intentional bit inversions among them with beyond the error correcting limitations of chosen code. Comparative results between proposed design and Rijndael algorithm is illustrated with the aid of Xilinx Simulation tool. This paper concludes that novel key generation technique by Error Control Algorithm of wireless communication channel is an alternative solution to the cryptosystems without S-box substitution and any lookup tables.