Advantages and drawbacks of multiplicative spread spectrum watermarking

In this work we investigate the performance of multiplicative spread spectrum (SS) watermarking. In order to make the analysis mathematically tractable, we make some simplifying assumptions, in that we assume that the host features are normally distributed and that attacks take the form of additive white Gaussian noise. After deriving the optimum decoder for the considered scenario, the performance of the system are derived in terms of achievable bit error rate. The results are compared to those achievable through additive spread spectrum watermarking and a classical quantization based scheme. The overall conclusion of the paper is that while keeping the general behavior of SS systems, the multiplicative SS scheme outperforms its additive counterpart for low to moderate attacks.