Automatic Variable Length Key Generation from Images and CRT

This paper proposes a strategic approach for the generation of a number of variable length keys from a selected image. In any symmetric key algorithm, the same key cannot be used for a longer time and this enforces the user to change the key frequently. Images have more features than text like color, edges, ridges etc. Hence these features facilitate us to generate many keys of variable length. To strengthen the security of key we are applying Chinese Remainder Theorem (CRT) on the selected values from the selected image. Our experimental results proved that keys of variable length suitable for any algorithm can be generated from featured image in a secure way by using Chinese Remainder Theorem.