Secure watermark verification scheme

Copyright protection of digital contents, as one of the most important application of digital watermarks, works by watermark verification. In traditional watermark authentication schemes, a prover exposed a watermark to be present in a digital data to the possible dishonest verifier. However, a potential attacker is able to spoil or remove the watermark entirely once classified information like the watermark or the embedding key is known. Some of previous schemes proposed as solutions have not really achieved desirable results. Their lack of security and validity is the most serious problem. In this paper, we propose a secure watermark verification scheme based on zero knowledge protocols and public-key encryption scheme in order to solve this problem. There is no secret information that can be used for removing watermark disclosed during the verification process. It has considerable advantages over previously proposed schemes in terms of security and validity