Towards the Design of a Stronger AES: AES with Key Dependent Shift Rows (KDSR)

Cloud data storage is a service offered by cloud computing for storing the data. Though it has a lot of benefits, the security of the stored data is one of its major concerns. Many models have been developed to address this issue. These models encrypt the data and store them. Advanced encryption standard (AES) is one of the encryption methods that has been used prevalently. This paper presents a model that tries to further strengthen the AES algorithm. It alters the shift row of the AES by making it key dependent. The key dependency enhances the security of the algorithm and the results show that the statistical pattern of the plaintext is dispersed over the cipher text, thereby, defending the plaintext from the cryptanalysis. Experimental results indicate that the dispersion ratio of the plaintext over the cipher text increases from 0.75 for AES to approximately 1 for the proposed model. The model is also analyzed using the coefficient of variation metric. The proposed model also exhibits a significant level of avalanche effect.