Integral Cryptanalysis of Reduced-Round Crypton Block Cipher

Crypton is a block cipher submitted as a candidate for the advanced encryption standard (AES). It is very efficient in hardware implementations and was designed by Chae Hoon Lim. In this paper, we construct some distinguishers between 4-round Crypton and a random permutation of the blocks space. By using integral Cryptanalysis and partial sum techniques, the distinguishers are used to attack on 5 and 6-round of Crypton. The data complexity of our attack is 2³³ on 5-round Crypton, 6 · 2³² against 6-round Crypton respectively. The Time complexity of our attack is 2³⁶ on 5-round Crypton, 2⁴⁶ against 6-round Crypton respectively.