Asymptotic Fingerprinting Capacity for Non-Binary Alphabets
Source: Cornell University
Watermarking provides a means for tracing the origin and distribution of digital data. Before distribution of digital content, the content is modified by applying an imperceptible WaterMark (WM), embedded using a watermarking algorithm. Once an unauthorized copy of the content is found, it is possible to trace those users who participated in its creation. This process is known as 'Forensic watermarking'. Reliable tracing requires resilience against attacks that aim to remove the WM. Collusion attacks, where several users cooperate, are a particular threat: differences between their versions of the content tell them where the WM is located. Coding theory has produced a number of collusion-resistant codes.