International Association
for Cryptologic Research

This study investigates and improves the differential cryptanalysis of the ARADI block cipher, a low-latency cryptographic system developed by the United States National Security Agency for memory encryption. The preliminary security assessment of ARADI revealed deficiencies that require additional examination. This study revisits and corrects the key recovery attack introduced by Bellini et al. (Indocrypt 2024). By correcting these mistakes, the research presents a precise 11-round key recovery method with revised attack complexities. Additionally, the analysis is expanded to introduce a key recovery attack for 12 rounds of ARADI, leaving the security margin of the cipher to only 4 rounds.