Hiding information in encrypted images with (t, n) secret sharing for IoT and cloud services

Privacy and security concerns have emerged with the rapid advancement of information technology and the exponential growth in data storage and cloud services. This paper addresses these issues in the context of the Internet of Things (IoT) and cloud services. Focusing on reversible data hiding in encrypted images (RDHEI), the study presents an innovative scheme based on (t, n) secret sharing using an expandable magic matrix-based data hiding, which offers flexible security levels. The scheme is designed to withstand hacker attacks by effectively dispersing risks through secret sharing, dividing the data into multiple shares. This ensures that leaking fewer than t shares does not compromise the entire data and provides a flexible parameter scheme. The use of the expandable magic matrix enhances both the embedding capacity and security, demonstrating the robustness of the proposed RDHEI scheme in protecting data in the digital age. Furthermore, our approach encrypts images at the IoT gateway rather than at the cloud server, enabling content owners to assert ownership claims—an ability not available in previous schemes. Experimental results confirm that our scheme maintains a constant concealment capacity of up to 4 bits per pixel (bpp), while safeguarding the confidentiality of the hidden data and preserving the randomness of the generated shares.