Research on a Block Encryption Cipher Based on Chaotic Dynamical System

In this paper, a novel block encryption cipher based on chaotic dynamical system is proposed. The algorithm operates on 64-bit plaintext blocks, and the key is 128 bits long. In round function, the logistic chaotic map and three algebraic group operations are mixed. As the algorithm is a Feistel network, it can be used for both encryption and decryption. Furthermore, the security of the algorithm is analyzed in details. The cryptanalyse results indicate that the algorithm has good diffusion and confusion properties, and it is very sensitive to the plaintexts and keys. Finally, by using differential cryptanalysis we found the upper bound of difference character capability for this cipher is 2^-6.6601 and 2^-17.1862 when block length is 16 and 32 bits long, respectively.