Survey of Public Key Digital Watermarking Systems

In traditional symmetric watermarking schemes, the key used for watermark embedding must be available at the watermark detector. This leads to a security problem if the detectors are implemented in consumer devices that are spread all over the world. So asymmetric watermarking schemes, also named public key digital watermarking schemes attract more and more attentions. In such a public key watermarking system, the private key is used for watermarking embedding and the public key is used only for watermarking detection. The private key is kept for secret, and the watermarks cannot easily be removed with public key. Several latest proposed public key watermarking schemes are reviewed in the paper, and their performances are analyzed.