Impossible differential cryptanalysis of Piccolo lightweight block cipher

This paper analyzes the Piccolo family of lightweight block ciphers against the impossible differential cryptanalysis. A combination of some ploys such as decreasing the S-box computations, finding an appropriate propagation of differentials, utilizing hash tables and using the linearity of the key-schedule as well as disregarding subkeys of two rounds lead to 12-round and 13-round impossible differential attack on Piccolo-80 and 15-round attack on Piccolo-128. The time and data complexity of the attack against Piccolo-80 is 2^55.18 and 2^36.34 for 12-round and 2^69.7 and 2^43.25 for 13-round, respectively. Moreover, the time and data complexity for 15 rounds cryptanalysis of Piccolo-128 are 2^125.4 and 2^58.7, respectively.