Image cryptography: The genetic algorithm approach

Evidently, information security is a sine qua non in the “modern life, With its sick hurry, its divided aims, Its heads o´ertaxed, its palsied hearts, ...”. To protect our data against unauthorized access, from the time immemorial the first choice has always been to use cryptography. With rapid growth in the arena of multimedia technology, since digital image has become an important medium of communication, extensive research is still a dynamic process in this field. We also have concentrated on image data encryption in this work. The effectiveness of the protection through encryption depends on the algorithm applied and as well as on the quality of the `key´ used. If a `key´ is badly designed or haphazardly selected, obviously the protection fails to provide proper security and improper access can be gained on the secured information. The first algorithm in cryptographic system design is the algorithm to generate `key´. It specifies the manner in which the `key´ is to be chosen. This work focuses on a totally new approach towards the `key´ generation for encryption algorithms. Here, Genetic Algorithm (GA), an important method of artificial intelligence has been applied to generate encryption `key´, which plays a vital role in any type of encryption. In our work, a hybridized technique called BlowGA is also proposed which is a combination of Blowfish and GA. Blowfish Algorithm is a conventional method of encryption. Our experimental observations show that the newly-proposed hybridized method BlowGA outperforms both GA and Blowfish Algorithm.