A Secure Reversible Data Hiding Scheme for Digital Images using Random Grid Visual Secret Sharing

A secure data hiding scheme based on visual secret sharing and histogram shifting is proposed. Visual secret sharing is used to encrypt the secret image before hiding it into the host image. Encryption is performed by dividing secret image into n shares. Out of these shares, n-1 are embedded in the host image, and one is stored as a secret key share with Trusting Authority. At the receiver side, the k out of these n-1 shares are extracted from the image. The complete secret data can be revealed only when the key share would be superimposed with the k retrieved shares. Random grid technique along with XOR operation has been used to create shares, resulting in no pixel expansion and maximum contrast for the extracted image. The shares have been embedded in the cover image by using the concept of histogram shifting.