A Threshold-based Steganographic Approach for Improved Security with Payload and PSNR

Abstract

It is essential to ensure data security in the modern world where all our important information is online. Security is the primary concern when sharing information over a communication network to avoid third parties. Steganography is the method of hiding secret data into a cover medium so that the data that will be transmitted cannot be detected by a third party. Steganography plays a vital in securing data over any network. Many steganographic methods have been introduced to ensure the transmission of data. Where image steganography is the well-known method. The main challenges in image steganography are the payload capacity of hidden data, imperceptibility, and robustness against unauthorized access. The Peak Signal to Noise Ratio (PSNR) can be low by hiding large amounts of secret data inside the image. Steganography and cryptography are interrelated, but cryptography converts plain text into cipher text to make it unreadable.In contrast, steganography is the method of hiding secret data in a cover image so that it is even unable to detect or guess the existence of any secret information. In this research, a method of threshold-based steganography is introduced. Secret data is encoded in the cover picture depending on a threshold of the cover image's colour levels after the cover image is scanned for all colour levels. We used the cover image's least significant bits (LSB) to embed the secret data. To improve payload, we encrypt-ensure security; we encrypted to ensure the encode it. The proposed method is implemented and analyzed on 512 × 512 sizes of coloured and greyscale images as a dataset using MATLAB tool. Our work outperforms the existing methods by attaining a 99% performance rate to achieve the best stego image that securely carries maximum secret data, i.e., Payload and security, along with other parameters.