Enhancing the Capacity and Robustness of an LSB Algorithm Using a Novel Insertion Method, Hashing Function, and Secret Key

Steganography hides a secret message inside another medium (cover-image) while maintaining imperceptibility and/or robustness/embedding capacity, making it a suitable candidate for keeping information safe and hiding the existence of data itself inside another medium. Secret data is susceptible to attacks or may be modified while steg-image is transiting through the Internet. The present paper explains how secret key steganography uses a new insertion method to hide information inside an image and a hashing function applied on the secret data. The SHA 256 function detects errors in data and assures its arrival without modifications. The proposed algorithm improves the security level by adding a robustness parameter (secret key and hash function) and creating a new insertion method that doubles the cover-image capacity to hide a secret message inside a color image compared with LSB, useful for keeping sensitive, relevant, and important information invulnerable. The results are compared with the LSB algorithm and related work in terms of the peak signal to noise ratio (PSNR) values, cover-image maximum capacity (MX), image quality index (Q), bit per pixel (BPP), processing time and robustness, showing that the proposed algorithm has a great balance between capacity and PSNR (big capacity with high PSNR level). It also increases the robustness level using secret key and hash function without affecting image imperceptibility. The proposed algorithm speed is outstanding, despite having complex calculations. This makes it eligible to be used in online platforms.