An Improved Algorithm to Watermark Numeric Relational Data.

This paper studies an improved algorithm to watermark numeric attributes in relational databases for copyright protection. It reviews related researches and presents an improved insertion algorithm, a detection algorithm and a recover algorithm. We introduce a varied-size grouping method in our insertion algorithm to insert a meaningful watermark. We also introduce a new mechanism to insert watermarks using the mark itself to decide marked positions. This insertion mechanism can be validated in our detection algorithm to decide whether a watermark exists or not. A badly destroyed marked relation or only a small part of it could still be detected successfully. Our recover algorithm introduces a competing mechanism to help recover the exact meaningful watermark after the detection result confirms the existence of the watermark. The experiments show it's robust to various attacks. [ABSTRACT FROM AUTHOR]