Traitor-Proof PDF Watermarking

TL;DR

This paper introduces a robust traitor-tracing watermarking method for PDF files that resists removal attempts and maintains document credibility, with analysis of payload options and privacy implications.

Contribution

It proposes a novel watermarking algorithm combining three techniques for traitor-proof PDF watermarking, including implementation and analysis of security and privacy aspects.

Findings

Watermarking withstands various attacks and resists removal.

The approach preserves document quality and watermarked document integrity.

Encryption schemes can reduce chilling effects on whistle-blowing.

Abstract

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.