Chinese Remainder Theorem-based Essential Secret Image Sharing

Zuquan Liu, Jianquan Yang, Guopu Zhu

Abstract: It is well known that the shares generated by most secret image sharing (SIS) schemes are of equal importance. However, in some essential SIS (ESIS) schemes, the generated shares are divided into two groups of different importance. The shares in the more important group are called essential shares, while the shares in the other group are called nonessential shares. In the phase of decryption, the secret image can be decrypted by a sufficient number of essential shares and some non-essential ones. Currently, the existing methods for constructing ESIS schemes have some shortcomings, such as explicit codebook requirements, size expansion, different share sizes, concatenation of sub-shares, and high computational complexity. To eliminate these drawbacks, a Chinese remainder theorem (CRT)-based ESIS scheme is proposed in this paper. The generated shares by the proposed approach have the equal size, and are not formed by concatenating sub-shares. Furthermore, the proposed approach has a low computational complexity since only modular operation is required in the decryption process. Finally, the experimental and comparative results show the validity and superiority of the proposed approach.