Improved LSB image steganography with high imperceptibility based on cover-stego matching

Abstract

Information security is an important factor when critical information is transferred. This paper concentrates on finding a method that can hide a message in an image without making any changes to it. The proposed method is novel and based on the Least Significant Bit (LSB) method with a high imperceptibility and capacity. Initially, the secret message bits are compressed using the LZW technique, then the compressed message bits are embedded into the LSB of the edge pixels in the cover image which have the same bit values. As a result, the cover image pixels remain unchanged and the stego image matches the cover image. The addresses of pixels that contain the compressed secret bits are maintained in a file called “location addresses” which the receiver uses to retrieve the compressed secret message. It is possible that the stego image will not be transmitted if it was previously specified by the sender and the receiver. Image quality metrics are applied to several standard images. The obtained PSNR for the stego image is infinity, SSIM and NCC are one, MSE and AD are zero for different embedding capacities in all images, which ensures the stego image's excellent imperceptibility.