Interpolation Attacks on Round-Reduced Elephant, Kravatte and Xoofff

Abstract

Abstract We introduce an interpolation attack using the Moebius Transform. This can reduce the time complexity to get a linear system of equations for specified intermediate state bits, which is general to cryptanalysis of some ciphers with update function of low algebraic degree. Along this line, we perform an interpolation attack against Elephant-Delirium, a round 2 submission of the ongoing national institute of standards and technology (NIST) lightweight cryptography project. This is the first third-party cryptanalysis on this cipher. Moreover, we promote the interpolation attack by applying it to the Farfalle pseudo-random constructions Kravatte and Xoofff. Our attacks turn out to be the most efficient method for these ciphers thus far.