Maximum average of differential probability is one of the security measures used to evaluate block ciphers such as the MISTY
cipher. Here
average means the average for all keys. Thus, there are keys which yield larger maximum differential probability even if the maximum
average of differential probability is sufficiently small.
This paper presents the cases in which the maximum differential probability is larger than the maximum average of differential
probability for some keys, and we try to determine the maximum differential probability considering the key effect.
Keywords Differential cryptanalysis - linear cryptanalysis - differential - maximum average of differential probability - linear hull - maximum average of linear probability - maximum non-averaged differential probability - maximum non-averaged linear probability - DES-like cipher