Error Diffusion Based Color Visual Cryptography for Secure Communication

Abstract: Color Visual Cryptography is the latest phenomenon for encrypting color secret images. Such secret messages are converted into number of color halftone image shares. The existing extended visual cryptographic schemes focused on gray scale and black and white visual cryptography schemes. These schemes are not suitable for color shares as they have different structures. There are some existing color visual cryptography schemes that might produce either meaningful or meaningless shares that produce less visual quality which lets people to suspect any kind of encryption involved in producing such shares. To overcome this problem, recently Kang et al. introduced error diffusion and the Visual Information Pixel (VIP) synchronization techniques to achieve color visual cryptography that can produce meaningful shares besides making the shares in such a way that they are pleasant to human eyes. In this paper implement the methods proposed by Kang et al. We also build a prototype application that demonstrates the proof of concept. The empirical results reveal that the proposed color visual cryptography can be used in real world applications.

Keywords: Meaningful color shares, error diffusion, visual cryptography, digital half toning, secret sharing