NayahStego: A Novel Digital Image Steganography Scheme for High-capacity and Secure Data Hiding in Spatial Domain

Information security plays a critical role in modern information technology, evolving to protect sensitive data during transmission. Steganography enhances confidentiality by embedding private information within publicly accessible multimedia content, effectively concealing it from detection. Although significant progress has been made in image steganography, achieving high security, adaptability, and embedding capacity while preserving image quality remains a persistent challenge. This study proposes NayahStego, a novel steganographic algorithm that adaptively exploits pixel neighbourhoods to embed secret data. NayahStego utilizes a pixel value differencing strategy combined with an overlapping embedding approach, selectively targeting pixel pairs based on their difference's magnitudes. The algorithm adaptively distributes secret bits across suitable pixels, reducing distortion and preserving visual quality. To enhance data extraction and image recovery, the method also references previously used embedding regions. Experimental results show that NayahStego outperforms existing methods, achieving an embedding capacity exceeding 100 kilobits and a Peak Signal-to-Noise Ratio (PSNR) of 97.58 dB for a 1-kilobit payload, demonstrating both its effectiveness and stego image's quality.