A new watermarking protocol against conspiracy

A trusted third party introduced in watermarking protocols would decrease the security and affect the implementation of the protocols. In this paper, a new watermarking protocol with an un trusted third party (UTTP) was proposed. Based on the idea of all-o>nothing disclosure of secret (ANDOS), all of the buyer, the seller and the third party didn't know the exact watermark, which was embedded in a digital content for tracing piracy. The proposed protocol pro vided mechanisms to trace piracy and protect customer's right, fn addition, the problem that a seller colluded with UTTP to frame the buyer, namely, the conspiracy problem, could be avoided.