Key-Dependent Dynamic SBox for KASUMI Block Cipher

The core strength of a block cipher lies in its nonlinear substitution operation, known as the SBox. However, the presence of static parameters within the SBox can potentially lead to the exposure of certain information in the ciphertext. In this paper, we present a methodology for the construction of key-dependent SBoxes. These key-dependent SBoxes exhibit resistance against linear and differential cryptanalysis. In this paper, we generate key-dependent 7-bit and 9-bit SBoxes for the KASUMI block cipher. Furthermore, we demonstrate their resistance against known differential fault attacks