High-Capacity Multi-secret Sharing by Random Grid

It´s well-known that visual secret sharing aims at encrypting a secret image into numerous meaningless sharing images by either designing a well-designed codebook or generating random bit sequence, and reconstructing the secret by superimposing them without any computation involved. However, the traditional visual secret sharing schemes only deal with one secret at a time. In this paper, the authors proposed a multi-secret sharing scheme by random grids such that the following advantages are obtained: 1) removing the restriction of limited secret images encrypted into two cipher-grids 2) removing the problem of suffering pixel expansion, and 3) without the need of designing tailor-made codebook.