Square Attacks on 3D Cipher

3D cipher is a new block cipher proposed in CANS 2008. It is different from all known block cipher as it uses the three dimension structure. According to the structure properties of 3D cipher, a new 5.25-round and a new 6.25-round square distinguishers are presented, and the square attacks on reduced- round 3D are improved. Attacking results demonstrate that 6-round attack is better than the known square attacks in data complexity and time complexity. Moreover, these two new distinguishers can be applied to 7/8/9-round 3D cipher.