A novel magic LSB substitution method (M-LSB-SM) using multi-level encryption and achromatic component of an image

Abstract: Image Steganography is a thriving research area of information security where secret data is embedded in images to hide its existence while getting the minimum possible statistical detectability. This paper proposes a novel magic least significant bit substitution method (M-LSB-SM) for RGB images. The proposed method is based on the achromatic component (I-plane) of the hue-saturation-intensity (HSI) color model and multi-level encryption (MLE) in the spatial domain. The input image is transposed and converted into an HSI color space. The I-plane is divided into four sub-images of equal size, rotating each sub-image with a different angle using a secret key. The secret information is divided into four blocks, which are then encrypted using an MLE algorithm (MLEA). Each sub-block of the message is embedded into one of the rotated sub-images based on a specific pattern using magic LSB substitution. Experimental results validate that the proposed method not only enhances the visual quality of stego images but also provides good imperceptibility and multiple security levels as compared to several existing prominent methods.

• The paper proposes a novel Magic LSB Substitution Method (M-LSB-SM) for image steganography using multi-level encryption and the achromatic component (I-plane) of HSI color space.
• The method employs a Magic LSB substitution technique with non-repetitive embedding indices dictated by a matrix, improving imperceptibility and resistance to steganalysis.
• Experimental results show superior performance over existing methods, achieving an average PSNR of 47.93 dB and enhancing security against unauthorized extraction.

A Novel Approach to Image Steganography: Magic LSB Substitution Method with Multi-Level Encryption

The paper "A Novel Magic LSB Substitution Method (M-LSB-SM) using Multi-Level Encryption and Achromatic Component of an Image" introduces a sophisticated approach to image steganography, focusing on enhancing imperceptibility and security within digital images. The method employs an innovative Magic LSB substitution technique coupled with multi-level encryption (MLE) and utilizes the achromatic component of an HSI color model, strategically departing from the conventional RGB model.

Methodology

The proposed methodology involves converting the input image to HSI color space, emphasizing the achromatic component (I-plane). This decision minimizes computational overhead and maximizes security by isolating the embedding process from highly correlated RGB channels. The I-plane is segmented into four sub-images, each rotated at distinct angles controlled by a secret key. Parallelly, the secret message undergoes division into four blocks followed by encryption through a multi-level encryption algorithm (MLEA), ensuring an enhanced layer of security.

Magic LSB substitution is applied within each sub-image following specific patterns dictated by a magic matrix deriving from MATLAB, dispersing the secret message bits in a manner that complicates extraction through steganalysis techniques. The use of a magic matrix introduces non-repetitive indices for embedding, disrupting predictability and enhancing the robustness of the stego image against statistical attacks.

Experimental Validation

Quantitative and qualitative evaluations underscore the efficacy of the proposed M-LSB-SM across multiple standard image datasets, including USC-SIPI-ID and COREL Database. The experiments cover a wide range of image dimensions and cipher sizes, consistently illustrating superior results in image quality assessment metrics such as PSNR, SSIM, NCC, and MAE. Notably, the proposed technique achieves an average PSNR of 47.93 dB, marking a substantial improvement over existing methods.

Comparative Analysis

The comparison spans seven prior techniques, including classical LSB, SCC, PIT, FMM, CST, SHSI, and Karim's methods. The M-LSB-SM excels in generating stego images that maintain high visual quality while embedding substantial payload capacities with refined imperceptibility. Remarkably, it combines the advantages of enhanced security, through encryption and strategic embedding, with high image quality—a feat less attainable by other methodologies within the listed compendium.

Implications and Future Prospects

The implications for digital security systems are profound. The methodology augments the protective barrier against unauthorized extraction amidst rapidly advancing steganalysis systems. Furthermore, the strategic use of a novel embedding mechanism complicates detection and breaches, affirming its relevance in safeguarding sensitive transmissions and documentation digitally.

Future researchers might explore extending MLEA’s capabilities, potentially transitioning the Magic LSB approach into the transform domain, optimizing resilience against statistical and image processing attacks. Such advancements would further cement the technique’s applicability and efficacy in the evolving landscape of information security.

Conclusively, the novel approach delineated in the Magic LSB substitution with MLE highlights both foundational improvements in steganographic practices and the progressive strides towards fortified digital encryption methodologies.