PERFORMANCE EFFICIENCY OF MODIFIED AES ALGORITHM USING MULTIPLE S-BOXES
Felicisimo V. Wenceslao, The Society of Digital Information and Wireless Communication · International Journal of New Computer Architectures and their Applications · 2015
In our previous paper, we modified the Advance Encryption System (AES) algorithm by proposing to use multiple substitution boxes (S-Boxes). While many studies have been conducted specifically on modifying the S-box, these studies were made to replace the Rijndael S-box in the AES cipher. Our version of the AES algorithm used two substitution boxes where the first S-box is the Rijndael S-box and was used as is. The second S-box was constructed by performing an XOR operation and affine transformation. Furthermore, the second S-Box replaced the MixColumns operation within the internal rounds in the cipher. This paper aims to determine the performance efficiency of the modified AES algorithm using multiple S-Boxes. Based on the result of the experiments, it was found out that the modified AES algorithm using multiple S-Boxes has an achieved execution time performance efficiency of 22.986 % for encryption and 109.76 % for decryption processes. However, when tested using the avalanche effect, the changes in the output bits were below the minimum expected rate at 24.219 % and 19.531 % respectively.