SAT Attacks on ARX Ciphers with Automated Equations Generation

We propose a novel and simple approach to algebraic attack on block ciphers with the SAT-solvers. As opposed to a standard approach, the equations for key expansion algorithms are not included in the formulas that are converted to satisfiability problem. The lack of equations leads to finding the solution much faster. The method was used to attack a lightweight block ciphers SIMON and SPECK. We report the timings for roundreduced versions of selected ciphers and discuss the potential factors affecting the execution time of our attack.