11th International Conference on ICT for Sustainable Development

Authors - A. Harshavardhan, Konkathi Nihal, Ramini Srinidhi, Konda Poojithasai, Gochika Bhanu prasad, Dhanraj Sai Ganesh
Abstract - This paper presents a novel, dual-layer secure steganographic system that combines hybrid cryptography and steganography to ensure the confidentiality, integrity, and security of secret communications. Initially, the sender inputs their message and selects a cover image. The message is encrypted using a hybrid substitution (playfair cipher and columnar transposition cipher) and transposition cipher, and then embedded in randomly selected pixel positions of the image using Least Significant Bit (LSB) steganography. A position file that records these embedding locations is generated and encrypted. To obfuscate the presence of the stego-image, multiple duplicate images are created alongside the steganographic image. On the receiver's side, a ResNet50-based feature extractor followed by K-means clustering is used to identify the stego-image from the duplicates. The encrypted position file enables accurate message extraction and subsequent decryption. Experimental results show excellent performance with high imperceptibility (MSE: 0.0175, PSNR: 65.69 dB, SSIM: 0.9994) and strong resilience to brute-force and statistical steganalysis.