Multiparty reversible data hiding in encrypted images based on secret sharing over dual Galois fields

Abstract

Multi-party reversible data hiding in encrypted images (MRDHEI) encrypts the original image into multiple encrypted images by adopting secret sharing over Galois field (GF). However, the MRDHEI methods based on secret sharing over GF(251) require special processing for pixels with values exceeding 250, while those based on secret sharing over GF(256) incur high computational overhead. To address these issues, an MRDHEI method based on secret sharing over GF(251) and GF(256) is proposed, in which the pixels are divided into two categories: the pixels with values ranging from 0 to 250 and the pixels with values ranging from 251 to 255. The two categories of pixels are encrypted using secret sharing over GF(251) and GF(256), respectively. A unified embedding algorithm is employed to embed secret data into encrypted images. The secret data can be accurately extracted and the original image can be losslessly recovered. Experimental results demonstrate that the proposed method achieves improved computational efficiency and embedding capacity while ensuring security.