Abstract
Advances in multimedia and networking technologies have enabled the infringement of digital content distributed over the internet. Consequently, several methods have been developed for copyright protection to identify illegal distributors through the World Wide Web (WWW). However, no agreed-upon mechanism exists for authenticating content provider websites or for preserving the integrity of their content. In this paper, we propose an effective and secure watermarking protocol that encapsulates a flexible and convenient solution for the content provider (CP) authentication and integrity problem. The security of the proposed protocol is based on the security of (PKI) and dual watermarking based on threshold cryptography. The proposed protocol exploit the existence of the trusted CA to solve collude problem and applying the idea of zero knowledge proof for verification purpose. The analysis results indicate the functional verification for encoder (watermark embedding), decoder (watermark extracting), encryption, decryption and hashing. Additionally, the evaluation results show better results for modified DWTC compared with other schemes (RP, WSC, and SSC) in terms of embedding time for large contents.