Combined Cryptography and Steganography for Enhanced Security in Suboptimal Images

Technology has developed to a very great extent, and the use of smart systems has introduced an increasing threat to data security and privacy. Most of the applications are built-in unsecured operating systems, and so there is a growing threat to information cloning, forging tampering counterfeiting, etc.. This will lead to an un-compensatory loss for end-users particularly in banking applications and personal data in social media. A robust and effective algorithm based on elliptic curve cryptography combined with Hill cipher has been proposed to mitigate such threats and increase information security. In this method, ciphertext and DCT coefficients of an image, embedded into the base image based on LSB watermarking. The ciphertext is generated based on the Hill Cipher algorithm. Hill Cipher can, however, be easily broken and has weak security and to add complexity, Elliptic curve cryptography (ECC), is combined with Hill cipher. Based on the ECC algorithm, the key is produced, and this key is employed to generate ciphertext through the Hill cipher algorithm. This combination of both steganography and cryptography results in increased authority and ownership of the data for sub-optimal media applications. It is hard to extract the hidden data and the image without the proper key. The performance for hiding text and image into an image data have been analyzed for sub-optimal multimedia applications.