Tracing Mobile Database with Complex Watermark

Relational database can be replicated and distributed in the mobile computing scenario. To protect the ownership of the data and to trace the trail of data distribution, we devise a complex database watermark scheme. In each data distribution process, the sender and the receiver agree on a watermark key pair, and a watermark is embedded into the data. In case of piracy or misusing, the sender can claim the ownership of the controversial data copy and accuse the receiver for his improper behavior. On the other hand, an innocent receiver can prove his innocence to arbitral authorities with watermark detection. Experiment results show that the scheme has a satisfying performance and it is qualified for practical use.