Secret Image Sharing with Public Reconstruction over Distributed Cloud Network

A well-known (k, n) secret image sharing (SIS) scheme is the threshold scheme to share a secret image into n shadow images, and the secret image can be recovered from any k shadow images. And, fewer than shadow images get nothing on the secret image. However, all previous SIS schemes do not deal with publicly reconstructing secret image over distribute cloud network (DCN). To enable secure public reconstruction over DCN, we need secure communication channels among all involved participants holding shadow images. A naive method is using an extra key management protocol to deliver a common key to all participants. In this paper, we propose the (k, n)-SIS over DCN (SISDCN), which still has the threshold property (recover the secret image from any k shadow images), and meanwhile provides secure public reconstruction over DCN, i.e., our SISDCN may noninteractively share a common key among any k participants.