ENHANCED ADVANCED ENRYPTION STANDARD (AES) WITH RANDOMIZED ROUND KEY AND SHIFT ROWS OPERATIONS

ABSTRACT

To prevent unauthorized access to data in transit, cryptographic methods are increasingly utilized. The most popular symmetric cryptographic technique is the Advanced Encryption Standard (AES). Due to its popularity, the algorithm become susceptible to cryptanalysis and brute force attacks as shown in several studies, hence the need to strengthen the algorithm. An enhanced AES with randomized round-key and shift-row operations was proposed. The idea behind the randomization of the operations is to achieve a higher avalanche effect. As a result, slight alteration in the plain text will significantly alter the cipher text. The proposed algorithm was implemented using Java and evaluated based on avalanche effect and execution time. Simulation results shows that enhanced AES achieved higher avalanche effect for AES 128, 192, and 256. This shows that the enhanced AES exhibits higher level of randomness as compared to the classical AES. However, slight increase in execution time was recorded.

Keywords: Cryptography, Encryption, AES, Enhanced AES, Round Key, Shift Rows