Secret Key-Based Image Steganography in Spatial Domain

Abstract

Day by day, the requirement for secure communication among users is rising in a digital world, to protect the message from the undesirable users. Steganography is a methodology that satisfies the user’s necessity of secure communication by inserting a message into different formats. This paper proposes a secret key-based image steganography to secure the message by concealing the grayscale image inside a cover image. The proposed technique shares the 20 characters long secret key between two clients where the initial eight characters of a secret key are utilized for bit permutation of characters and pixels while the last 12 characters of secret key decide the encryption keys and position of pixels of a grayscale image into the cover. The grayscale image undergoes operation such as encryption and chaotic baker followed by its hiding in a cover to form a stego image. The execution of the proposed strategy is performed on Matlab 2018. It shows that the proposed approach manages to store the maximum message of size 16[Formula: see text]KB into the cover of size [Formula: see text]. The image quality of stego images has been evaluated using PSNR, MSE. For a full payload of 16[Formula: see text]KB, PSNR is around 51[Formula: see text]dB to 53[Formula: see text]dB which is greater than satisfactory PSNR.