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

Abstract

A nonlinear substitution operation of bytes is the main strength factor of the Advanced Encryption Standard (AES) and other modern cipher systems. In this paper we have presented a new simple algorithm to generate key-dependent S-boxes and inverse S-boxes for block cipher systems. The quality of this algorithm was tested by using NIST tests, and changing only one bit of the secret key to generate new key-dependent S-boxes. The fact that the S-boxes are key-dependent and unknown is the main strength of the algorithm, since the linear and differential cryptanalysis require known S-boxes. In the second section of the paper, we analyze S-boxes. In the third section we describe the key-dependent S-boxes and inverse S-boxes generation algorithm. Afterwards, we experimentally investigate the quality of the generated key-dependent S-boxes. Comparison results suggest that the key-dependent S-boxes have good performance and can be applied to AES.

A Novel Method to Design S-Boxes Based on Key-Dependent Permutation Schemes and its Quality Analysis

“…These algorithms will increase the security of the cipher systems. As compared with algorithm in the paper [14], these algorithms generate S-boxes about eight times faster. For measure of the quality of the permuted S-boxes we have proposed to use eight distance metrics.…”

“…A keydependent S-box of AES algorithm using a variable mapping technique is analyzed in [13]. A key-dependent S-box generation algorithm in AES block cipher system is proposed in the paper [14]. Hamdy et al [15] have proposed a customized version of the AES block cipher in which the keydependent S-box generation algorithm is used.…”

“…These algorithms use some key-dependent permutations of the elements of the initial substitution box Sbox to get key-dependent substitution box Sboxm. Algorithm 1 was proposed in the paper [18].…”

“…We have assumed the Matlab function "randperm" as standard of permutation of the integer numbers. Hence, we could evaluate the performance of our four algorithms comparing the averaged normalized distances In equation (18) and Table IV …”

Enhancing the Security of AES Algorithm using Quantum Three-Pass Protocol

“…Diffusion is the spreading of the influence of a plaintext bit onto many cipher text bits to hide the statistical structure of the plaintext. These two properties in AES are achieved by round repetition and using S-box [12]. Due to this, it is considered as one of the most secure cryptosystem.…”