Improved Biclique Cryptanalysis of the Lightweight Block Cipher Piccolo
Guoyong Han, Wenying Zhang · Security and Communication Networks · 2017
Biclique cryptanalysis is a typical attack through finding a biclique which is a type of bipartite diagram to reduce the computational complexity. By investigating the subkey distribution and the encryption structure, we find out a weakness in the key schedule of Piccolo-80. A 6-round biclique is constructed for Piccolo-80 and a 7-round biclique for Piccolo-128. Then a full round biclique cryptanalysis of Piccolo is presented. The results of the attacks are with data complexity of 240and 224chosen ciphertexts and with computational complexity of 279.22and 2127.14, respectively. They are superior to other known results of biclique cryptanalytic on Piccolo.