Reversible Data Hiding in Encrypted Images Using Cipher-Feedback Secret Sharing.

Reversible data hiding in encrypted images (RDH-EIs) has attracted increasing attention since it can protect the privacy of original images while exactly extracting the embedded data. In this paper, we propose an RDH-EI scheme with multiple data hiders. First, we introduce a cipher-feedback secret sharing (CFSS) technique using the cipher-feedback strategy of the Advanced Encryption Standard. Then, using the CFSS technique, we devise a new $(r,n)$ -threshold ($r\leq n$) RDH-EI scheme with multiple data hiders called CFSS-RDHEI. It can encrypt an original image into $n$ encrypted images with reduced size using an encryption key and sends each encrypted image to one data hider. Each data hider can independently embed secret data into the encrypted image to obtain a marked encrypted image. The embedded data can be extracted from each marked encrypted image using the data hiding key, and the original image can be completely recovered from $r$ marked encrypted images using the encryption key. Performance evaluations show that our CFSS-RDHEI scheme has a higher embedding rate and that its generated encrypted images are much smaller, while still being well protected, compared to existing secret sharing-based RDH-EI schemes. [ABSTRACT FROM AUTHOR]