New Results in Related Key Impossible Differential Cryptanalysis on Reduced Round AES-192

The security of a crypto system is usually measured through the application of different types of cryptanalysis methods. Cryptanalysis using impossible differentials is found to be an effective method for retrieving the keys of block ciphers. Concept of Related keys is used to extend the number rounds with which an impossible condition is created, so that the attack complexity can be reduced. In this paper, a new related key is proposed and reduced round attacks are carried out to measure the cryptographic strength of AES 192. Following the 7 round attack proposed in [1], an 8 round attacks is proposed using a new relative key, which retrieves the keys with the least time complexity.