Cryptanalysis of ARX-based White-box Implementations

At CRYPTO’22, Ranea, Vandersmissen, and Preneel proposed a new way to design white-box implementations of ARX-based ciphers using so-called implicit functions quadratic-affine encodings. They suggest the Speck block-cipher as an example target.In this work, we describe practical attacks on construction. For implementation without one external encodings, simple algebraic key recovery attack. If both encodings are used (the main scenario suggested by authors), propose optimization inversion attacks, followed our result - multiple-step round decomposition attack decomposition-based attack.Our only use oracles do not rely their description. We implemented verified experimentally instances Speck-32/64 Speck-64/128. conclude that single ARX-round is too weak be round.