Partly-Pseudo-Linear Cryptanalysis of Reduced-Round S<span style="font-variant: small-caps">peck</span>

Abstract

We apply McKay’s pseudo-linear approximation of addition modular 2n to lightweight ARX block ciphers with large words, specifically the Speck family. We demonstrate that a pseudo-linear approximation can be combined with a linear approximation using the meet-in-the-middle attack technique to recover several key bits. Thus we illustrate improvements to Speck linear distinguishers based solely on Cho–Pieprzyk approximations by combining them with pseudo-linear approximations, and propose key recovery attacks.

Keywords

• peck%22%2C%22default_operator%22%3A%22AND%22%7D%7D%7D"> S<span style="font-variant: small-caps">peck</span>
• pseudo-linear cryptanalysis
• linear cryptanalysis
• partly-pseudo-linear attack