Enhanced Collusion Resistance for Segment-wise Recombined Fingerprinting in P2P Distribution Systems

摘要

Recombined fingerprinting has been recently proposed as a scalable alternative to the traditional client-server model for anonymous fingerprinting. In recombined fingerprinting, the contents are distributed in P2P fashion from a few seed nodes to the rest of buyers. However, the solution of the previous works requires that a hash of the whole fingerprint is also constructed during distribution in such a way that two different codes must be used (one at segment level and one at hash level). This solution is impractical for two reasons: (1) the fingerprint's length is increased, and (2) the construction of the fingerprints through recombination must be supervised in order to obtain a valid hash-level codeword. This work contributes with a solution to this problem, consisting of embedding collusion-resistant codewords only at segment level and removing the need for hash-level encoding. The proposed solution not only results in shorter fingerprints, but also simplifies the distribution protocol since supervision is no longer required. The resulting system is shown to work for four different state-of-the-art collusion-resistant codes by means of thousands of simulations.