Design and Anti-collusion Performance Analysis of a Quantization Based Orthogonal Fingerprinting Scheme

Multimedia fingerprinting is a technique to trace illegal redistribution of digital representations of multimedia content and to combat multi-user collusion attack. Among existing collusion resistant fingerprinting schemes, spread spectrum (SS) orthogonal fingerprinting has the best collusion resistance in non-blind detection, but in blind detection it shows inadequate performance. In this paper, we propose a novel quantization based orthogonal fingerprinting (QOFP) scheme that possesses good performance in non-blind and blind scenarios. To generate one fingerprinted copy, we implement subtractive dither quantization to the host signal with a dither sequence. By letting the elements in all dither sequences follow independent and identically distributed uniform distribution over a quantization step size, we make fingerprints embedded in different copies mutually orthogonal. Compared with SS orthogonal fingerprinting, our proposed QOFP has almost identical collusion resistance in non-blind detection and much better collusion resistance in blind detection.