Key-Dependent S-Box Generation in AES Block Cipher System

Abstract

Advanced Encryption Standard (AES) block cipher system is widely used in cryptographic applications. A nonlinear substitution operation is the main factor of the AES cipher system strength. The purpose of the proposed approach is to generate the random S-boxes changing for every change of the secret key. The fact that the S-boxes are randomly key-dependent and unknown is the main strength of the new approach, since both linear and differential cryptanalysis require known S-boxes. In the paper, we briefly analyze the AES algorithm, substitution S-boxes, linear and differential cryptanalysis, and describe a randomly key-dependent S-box and inverse S-box generation algorithm. After that, we introduce the independency measure of the S-box elements, and experimentally investigate the quality of the generated S-boxes.

An Algorithm for Key-Dependent S-Box Generation in Block Cipher System

“…The additional time needed to generate key-dependent S-boxes is negligible. As compared with algorithm in the paper Kazlauskas and Kazlauskas (2009), this algorithm generates S-boxes about eight times faster.…”

“…A key-dependent S-box of AES algorithm using a variable mapping technique is analyzed in Mohammad et al (2009). A key-dependent S-box generation algorithm in AES block cipher system is proposed in the paper of Kazlauskas and Kazlauskas (2009). Hamdy et al (2011) have proposed a customized version of the AES block cipher in which the key-dependent S-box generation algorithm is used.…”

Image Encryption Using Elliptic Curves and Rossby/Drift Wave Triads

“…Furthermore, the following facts put our scheme in a favorable position: Our scheme uses a dynamic S-box for each input image while the S-box used in [ 29 ] is a static one, which is vulnerable [ 63 ] and less secure than a dynamic one [ 64 ]. The presented scheme guarantees an S-box for each image, which is not the case in [ 31 ].…”

Two-Key Dependent Permutation for Use in Symmetric Cryptographic System

“…An -box generation method through compositions of permutations from some fixed set using random bijective methods has been discussed in [18]. Pseudorandom -boxes generated using a secret key for AES Block cipher has been described in [19]. Cryptographically key-dependent -box design using a four-dimensional hyperchaotic Chen system and its suitability for designing block cipher with dynamicboxes satisfying the -box design criteria is suggested in [20].…”