Research on Enhanced AES Algorithm Based on Key Operations

AES is recognized as one of the most secure symmetric encryption algorithms and has been widely used in the field of information security. It has the advantages of simplicity, efficiency, symmetry, modularity, etc., but there are many attacks against AES, such as differential attack, linear attack, side channel attack, etc., which requires us to further study the methods to enhance the security of AES algorithm. This paper presents an enhanced AES algorithm based on key operation. The traditional SubBytes operation in AES replacing the current state matrix with values obtained from the S-box. and the ShiftRows is that every row of the state matrix is rotated to the left according to the fixed bit, while the improved method mentioned in this paper is to associate the SubBytes and ShiftRows with the key in the calculation process. After the improvement of SubBytes, the current state matrix and the KV value calculated by the wheel key matrix are XOR operation to get a new state matrix, and the new state matrix is used to replace the S-box. The ShiftRows improvement is to dynamically shift the state matrix by comparing the KV values obtained from the calculation of the wheel key. The efficiency of the algorithm will be reduced slightly due to the introduction of key-related operations in the process of this improvement scheme, but it is worthwhile to improve the security of the algorithm on the basis of the small decrease in efficiency. Experiments show that the improved AES algorithm has better avalanche effect than the traditional AES algorithm.