A Survey on Reversible Image Data Hiding Using the Hierarchical Block Embedding Technique

The use of graphics for data concealment has significantly advanced the fields of secure communication and identity verification. Reversible data hiding (RDH) involves hiding data within host media, such as images, while allowing for the recovery of the original cover. Various RDH approaches have been developed, including difference expansion, interpolation techniques, prediction, and histogram modification. However, these methods were primarily applied to plain photos. This study introduces a novel reversible image transformation technique called Block Hierarchical Substitution (BHS). BHS enhances the quality of encrypted images and enables lossless restoration of the secret image with a low Peak Signal-to-Noise Ratio (PSNR). The cover image is divided into non-overlapping blocks, and the pixel values within each block are encrypted using the modulo function. This ensures that the linear prediction difference in the block remains consistent before and after encryption, enabling independent data extraction without picture decryption. In order to address the challenges associated with secure multimedia data processing, such as data encryption during transmission and storage, this survey investigates the specific issues related to reversible data hiding in encrypted images (RDHEI). Our proposed solution aims to enhance security (low Mean Squared Error) and improve the PSNR value by applying the method to encrypted images

An Improved Reversible Data Hiding with Hierarchical Embedding for Encrypted Images and BBET

This research introduces an enhanced reversible data hiding (RDH) approach incorporating hierarchical embedding for encrypted images and employs a novel technique termed BBET (Best Bits Embedding Technique). RDH involves concealing information within a host sequence, enabling the restoration of both the host sequence and embedded data without loss from the marked sequence. While RDH has traditionally found applications in media annotation and integrity authentication, its utilisation has expanded into diverse fields. Given the rapid advancements in digital communication, computer technologies, and the Internet, ensuring information security poses a formidable challenge in safeguarding valuable data. Various reversible and stenographic techniques exist for covertly embedding or protecting data, spanning text, images, and protocols, and facilitating secure transmission to intended recipients. An influential approach in data security is reversible data hiding in encrypted images (RDHEI). This paper distinguishes between the conventional RDHEI technique, characterised by lower Peak Signal-to-Noise Ratio (PSNR) and higher Mean Squared Error (MSE), and proposes an improved RDHEI technique. As the prevalence of digital techniques for image transmission and storage rises, preserving image confidentiality, integrity, and authenticity becomes paramount. Text associated with an image, such as authentication or author information, can serve as embedded data. The recipient must adeptly recover both the concealed data and the original image. Reversible data-hiding techniques ensure the exact recovery of the original carrier after extracting the encrypted data. Classification of RDHEI techniques is based on the implemented method employed. This paper delves into a comprehensive exploration of techniques applicable to difference expansion, histogram shifting, and compression embedding for reversible data hiding. Emphasis is placed on the necessity for a reversible data-hiding technique that meticulously restores the host image. Furthermore, the study evaluates performance parameters associated with encryption processes, scrutinising their security aspects. The investigation utilises the MATLAB tool to develop the proposed BBET technique, comparing its efficacy in embedding and achieving enhanced security features. The BBET technique is characterised by reliability, high robustness, and secure data hiding, making it a valuable addition to the evolving landscape of reversible data hiding methodologies