On dynamic chaotic S-BOX

The substitution table or S-box is considered as the core of the block ciphers. The good design of the S-box can increase the cipher security and simplicity. The aim of this paper is to demonstrate the efficiency of the dynamic S-boxes based on one-dimensional chaotic maps compared to classic S-box and to evaluate the more suitable one dimensional map to construct a dynamic S-box used in the AES algorithm. The security analysis shows that the dynamic S-boxes based on one-dimensional chaotic map (logistic and PWLCM) have very low linear and differential probabilities. In fact, they have better immunity against linear attacks than static S-box and comparable differential probability value. The new investigated criterion is the strict avalanche criterion (SAC). The results show that the piecewise linear chaotic map (PWLCM) has the closest value to 0.5. In order to validate the efficiency of the S-boxes and their inverse S-boxes images were encrypted using the modified AES algorithm and their histograms were compared. We find that dynamic chaotic S-boxes have slightly more uniform histograms than static S-box, so the AES using dynamic chaotic S-box is secure and as efficient as the classic algorithm.