Secret Image Sharing Based on Error-Correcting Codes

In traditional (k, n) threshold secret image sharing (SIS), a secret image is encrypted into n shadow images (also called shares) distributed to n associated participants. The secret image can be recovered by collecting any k or more shadow images, i.e., SIS is loss-tolerant. In SIS research domain, visual cryptography scheme (VCS) also called visual secret sharing (VSS) and Shamir's polynomial-based SIS scheme are the primary branches. Whereas, VCS mainly focuses on lossy recovery for binary secret image with pixel expansion, and most Shamir's polynomial-based SIS is not directly lossless. In this paper, we propose a SIS scheme based on error-correcting codes. Error-correcting code has the features of loss-tolerant and lossless recovery due to it has the strict mathematical relations of information values and check values, which has been widely used in signal communications. The loss-tolerant and lossless recovery features of error-correcting codes are utilized in the proposed scheme to achieve (k, n) threshold SIS with really lossless recovery. In addition, in the proposed scheme the size of each shadow image is smaller than the size of the original secret image. Experiments are conducted to evaluate the efficiency of the proposed scheme.