Paper 2024/1324 Original: eprint.iacr.org/2024/1324 ↗

CLAASPing ARADI: Automated Analysis of the ARADI Block Cipher

Abstract

In early August 2024, three NSA researchers -- Patricia Greene, Mark Motley, and Bryan Weeks -- published the technical specifications for a new low-latency block cipher, ARADI, along with its corresponding authenticated encryption mode, LLAMA, which is specifically designed for memory encryption applications. Their manuscript offered minimal security analysis of the design, only briefly discussing the differential, linear and algebraic properties of cipher's underlying components. In this work, we present a set of distinguishers for the round reduced ARADI block cipher, discovered using the automated cryptanalysis tool CLAASP. More precisely, using CLAASP, we evaluate the resistance of ARADI against avalanche, statistical and continuous diffusion tests, differential and linear distinguishers, impossible differentials, algebraic attacks, and neural distinguishers. Accordingly, we give distinguishers that reach up to 9 out of 16 rounds of ARADI. We hope these preliminary findings will encourage further in-depth cryptanalysis of the cipher to enhance confidence in its security.