## Cryptology ePrint Archive: Report 2020/689

Single Tweakey Cryptanalysis of Reduced-Round SKINNY-64

Orr Dunkelman and Senyang Huang and Eran Lambooij and Stav Perle

Abstract: Skinny is a lightweight tweakable block cipher which received a great deal of cryptanalytic attention following its elegant structure and efficiency. Inspired by the Skinny competitions, multiple attacks on it were reported in different settings (e.g. single vs. related-tweakey) using different techniques (impossible differentials, meet-in-the-middle, etc.). In this paper we revisit some of these attacks, identify issues with several of them, and offer a series of improved attacks which were experimentally verified. Our best attack can attack up to 18 rounds using $2^{60}$ chosen ciphertexts data, $2^{116}$ time, and $2^{112}$ memory.

Category / Keywords: secret-key cryptography / Skinny, differential cryptanalysis, block ciphers, cryptanalysis