A TTP watermarking protocol based on visual cryptography

With the development of information technology, big data has had a positive impact on the development of various industries. All kinds of digital data trading platforms have been established accordingly. However, when the original data buyer illegally distributes the digital data that he has bought through the data trading platform, the copyright protection problem arises. Watermarking protocols designed for tracing illegal distributors when unauthorized copies are found provide good solutions for the above problem. Classic buyer-seller watermarking protocols are designed for two-party transaction models, not fit for the data trading platform-based tripartite transaction model. In this paper, the author proposes a TTP (Trusted Third Party) watermarking protocol based on visual cryptography for the tripartite transaction model. As far as we know, our proposed scheme is the first watermarking protocol for tripartite transaction models. Besides, by introducing computation-cheap visual cryptography, our scheme provides a good balance between some contradictory requirements, such as security versus efficiency. Through the security analysis, it can be found that the proposed scheme can solve the problems reported in the existing literatures and achieves several improvements over other schemes.