Biclique Cryptanalysis of the Full-Round KLEIN Block Cipher.
Zahra Ahmadian, Mahmoud Salmasizadeh, Mohammad Reza Aref · 2013
Abstract. In this paper we present a biclique attack on the newly proposed block cipher KLEIN-64. We first introduce some weaknesses of the diffusion layer and key schedule of this algorithm. Then we exploit them to present a full round attack on KLEIN-64 using an asymmetric biclique. The (worst case) computations and data complexity of this attack are 2 62.84 and 2 39, respectively. A modified version of this attack is also presented which is slightly faster at the expense of the data required.