Straightforward Guess and Determine Analysis Based on Genetic Algorithm

With the development of artificial intelligence, the genetic algorithm has been widely used in many fields. In cryptography, the authors find it is natural to code an individual and design its fitness in a genetic algorithm for a straightforward guess and determine analysis (SGDA, in short). Based on this observation, the authors propose an SGDA based on genetic algorithm. Comparing it with the other three SGDAs based on exhaustive search, MILP method and CPP method respectively, the authors illustrate its effectiveness by three stream ciphers: Small scale SNOW 2.0, medium scale Enocoro-128v2 and large scale Trivium. The results show our method is significantly superior to them, especially for Trivium, the method can find a solution of 165 variables in less than one hour, while the other three methods are not applicable due to its enormous search space of size 2^619.37. As far as we know, it is a best solution in an SGDA for Trivium so far.