A robust image cryptography scheme using optimal band selection and dynamic key embedding

Abstract

Secure Image transmission over media like internet has become very important these days. Several techniques for enhancing security during image transmission like cryptography, steganography, etc. evolved over a period of time. In all these techniques, the images are converted to a form that is not detectable by the intermediate user except the sender and the authenticated user. Still these techniques have limitations in ensuring security in the transmission of secret images due to several attacks in the channel through which they are transmitted. In this paper, an approach of embedding secret information in a host image is carried out using a method of selecting the room for embedding in an optimal way to make the model robust against attacks. Further, an optimal way of key embedding is carried out on the selected band. The encrypted image obtained during the above mentioned steps is subjected to several attacks and the effected image is decrypted and the results are compared with the original host image with respect to the metrics like Peak Signal to Noise Ratio (PSNR), Mean Squared Error (MSE) and Normalized Cross Correlation (NCC). This proposed method is applied on several images and the above-mentioned metrics are obtained. The proposed approach proves to outperform the conventional LL band selection and LSB Key embedding methods.