Two-Round Iterative Characteristics for Linear Cryptanalysis of Modified DES with Embedded Parity Checks

We investigate two classes of 2-round iterative linear characteristics for DES-like ciphers obtained by embedding parity checks in the S-boxes of the original DES. This study complements our previous work [Linear Cryptanalysis and Modified DES with Parity Check in the S-boxes, LNCS 9540 (2016), pp. 60-78].