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The Advanced Encryption Standard (AES) is using in a large scale of applications that need to protect their data and information. A nonlinear substitution operation is the main factor of the AES cipher system strength. The S-Box component that used in AES is fixed, and not changeable. The purpose of the proposed approach is to use dual keys in encryption and decryption processes in SubByte transformation function. The first key generate multi random S-boxes depend on using multi keys that led to generate Sboxes provided that each one has its inverse associated with it, the second key is a random distribution of the S-boxes, the dual keys lead in increasing the complexity degree within the same delay time during the encryption and decryption processes in SubByte function. The results show that the present proposed algorithm has good cryptographic strength, with the added benefit that is resistant to linear and differential cryptanalysis, which require that the S-boxes be known beside the encryption key. General Terms Security, Algorithms, system strength, Plaintext, Ciphertext |
