Joint Multiple Watermarking and Non-Expansion Visual Cryptography

Abstract

This paper proposes a scheme to hide two watermarks in visual secret sharing of a gray level image. One watermark is embedded during secret image halftoning, and the other watermark is hidden during the halftone image encryption. A non-expansion visual secret sharing model is used to encrypt the halftone image. In data extraction, only exclusive-OR operation is needed. Experimental results show the effectiveness of our scheme.