Paper 2013/511

Low Data Complexity Biclique Cryptanalysis of Block Ciphers with Application to Piccolo and HIGHT

Siavash Ahmadi, Zahra Ahmadian, Javad Mohajeri, and Mohammad Reza Aref

Abstract

In this paper, we present a framework for biclique cryptanalysis of block ciphers with an extremely low data complexity. To that end, we enjoy a new representation of biclique attack. Then an algorithm for choosing two dierential characteristics is also presented to simultaneously minimize the data complexity and control the computational complexity. Then we characterize those block ciphers that are vulnerable to this technique and among them, we apply this attack on lightweight block ciphers Piccolo-80, Piccolo-128 and HIGHT. The data complexities of these attacks are considerably less than the existing results. For full-round Piccolo-80 and 128, the data complexity of the attacks are only 16 plaintext-ciphertext pairs and for full-round HIGHT our attack requires 256 pairs. In all attacks the computational complexity remains the same as the previous ones or even it is slightly improved.