Random grid-based visual cryptography with identifiable shares

This paper proposes a visual cryptography (VC) by a random grid (RG) scheme with identifiable shares. The method encodes an image in two shares that exhibits the following features: 1. each generated share is a RG with the same scale as ; 2. any share singly reveals no secret information on ; 3. the secrets can be revealed by superimposing the two generated shares; 4. folding up a share will display the identification patterns associated with it; and 5. both of the secret information and the identification patterns are recognized by the naked eye without any computation. The property to show identification patterns by simply folding it up is novel to visual cryptographic schemes in the literature. It provides useful information to identify the pair of shares belonging to a secret image, and establishes a simple and friendly interface for users to distinguish among and manage the numerous shares created by VC schemes.