Generation of AES S-boxes with Various Modulus and Additive Constant Polynomials and Testing their Randomization
Suman Das, Jesse Zaman, Ranjan Ghosh · Procedia Technology · 2013
In AES, the standard S-Box is usually generated by using a particular irreducible polynomial {11B} in GF(28) as the modulus, with a particular additive constant {63}. In this paper, it has been shown that, by maintaining the criteria defined by Rijndael, other moduli and constants can also be used to generate different unknown S-Boxes, thus preventing linear and differential cryptanalysis. A comparative study has been made on the randomness of AES ciphertexts generated, using these S-Boxes, by the NIST Test Suite coded by us. It has been found that besides using the standard one, other modulus polynomials and additive constants are also able to generate equally or better random ciphertexts. Moreover, they can act as additional key-inputs to AES, thus increasing the key-space.