This paper presents a traitor-tracing technique based on the watermarking of digital documents (\pdf{} files in particular). The watermarking algorithm uses a chain of three separate techniques that work in synergy. The embedded payload can withstand a wide range of attacks and cannot be removed without invalidating the credibility of the document. We will present an implementation of the approach and discuss its limitations with respect to documents that can be watermarked and quality of the watermarked documents. We will also analyse two payload alternatives and how the encryption scheme may alleviate the chilling effect on whistle-blowing.

翻译：本文介绍了一种基于数字文件(特别是\pdf ⁇ }文件)水标记的叛国追踪技术。水标记算法使用三套相互配合的不同技术链。嵌入的有效载荷能够承受各种攻击,在不取消文件的可信度的情况下是无法拆除的。我们将介绍该方法的实施情况,并讨论其在可加水标记的文件和水标记文件质量方面的局限性。我们还将分析两种有效载荷替代品以及加密办法如何减轻对吹哨的寒冷效应。