Watermarking protocols: an excursus to motivate a new approach

Digital watermarking is one of the techniques that can be used to support digital copyright protection. It enables copyright owners to insert a perceptually invisible watermark within any copy of content that is distributed on the Internet. The main aim is to use watermarks to implement copyright identification and content tracking. However, digital watermarking is not sufficient to ensure an adequate copyright protection, if it is not employed in conjunction with watermarking protocols, which define the schemes of the web transactions by which buyers can purchase protected digital content distributed by content providers in a secure manner. Therefore, watermarking protocols play a central role in the field of digital copyright protection by means of watermarking techniques. They have to ensure both a correct content protection and an easy participation of buyers in the purchase transactions of the contents distributed on the Internet. This paper presents a new watermarking protocol based on an innovative, buyer centric, and mediated design approach. The result is a secure protocol that enables buyers to easily participate in the transactions by which they can buy digital protected content, and this makes the protocol suited for the current web context.