Encryption Approach for Images Using Bits Rotation Reversal and Extended Hill Cipher Techniques
A new method for image encryption with two stages has been described in the present study. In first stage, each pixel of image is converted to its equivalent eight bit binary number and in that eight bit number, number of bits equal to the length of password are rotated and then reversed. In second stage, extended hill cipher technique is applied by using involuntary matrix generated by same password given in second stage to make encryption more secured. Performance of the proposed technique is evaluated by Statistical Analysis, Differential Analysis and also quantifying Mean Square Error (MSE) & Peak Signal to Noise Ratio (PSNR). The proposed approach is implemented for different images using MATLAB. Decryption involves the reverse of encryption.