With the development of digital watermarking technology, digital watermarking protocol is now drawing the attention for protecting copyrights of digital products. However, the copyright protection is fully protected by watermark technology if it is employed a suitable protocol between the rights owner and the customer. Therefore, currently, there are a number of buyer-seller watermarking protocols proposed, however, an anonymous problem and collusion problem are still unsolved completely. Thus, this paper proposes a high security watermark protocol based on iris biometric for resolving these problems. In addition, this paper also produces watermarking generation mechanism which aims to improve the efficiency of the whole mechanism. Finally, the investigation indicates that the proposed buyer-seller watermark protocol takes care of the security concerns of all parties involved, and the proposed scheme could also find an illegal copy of the content, the violators can be traced back.