Application of Genetic Algorithm in Cryptanalysis of Mono-alphabetic Substitution Cipher

Today, security is a vital concern in computer science, cryptography is used vastly for implementation of the same. Cryptanalysis is a process in which the security is attempted to breach and the complexity of this process is considered as security measurement. As cryptographic algorithm is open to all, the whole strength lies in the complexity of the key i.e. efforts to crack the key. Mostly the strength of the key is shown through its length, eventually the number of communication (Brute-force method). Genetic algorithms are considered to be a tool for meta heuristic applications. In this work an attempt is made to carry out cryptanalysis, through genetic algorithms. In this, mono-alphabetic substitution cipher technique is considered. The experiment is carried out for four key samples, and attempt to break with variations in genetic operators i.e. selection, crossover and mutation. Regarding variations, for selection- random with elitism, roulette wheel and tournament options are used, for crossover - 1-point, 2-point and Uniform options are used, with interchanging mutation.