Region incrementing visual secret sharing scheme based on random grids

A region incrementing visual secret sharing (RIVSS) scheme can incrementally reveal secrets with different secrecy levels. Recently, Wang proposed a 2-level incrementing visual cryptography using random grids, which can incrementally reveal the secrets on an image without pixel expansion. However, Wang´s scheme can only deal with 2-level RIVSS. In this paper, a novel region incrementing visual secret sharing (RGRIVSS) scheme based on (k, n)-threshold random grid is proposed. The proposed RGRIVSS scheme can deal with more than 2-level region incrementing VSS. The experimental results demonstrate the feasibility of the proposed scheme.