A Robust, Distortion Minimizing Technique for Watermarking Relational Databases Using Once-for-All Usability Constraints

Ownership protection on relational databases--shared with collaborators (or intended recipients)--demands developing a watermarking scheme that must be able to meet four challenges: 1) it should be robust against different types of attacks that an intruder could launch to corrupt the embedded watermark; 2) it should be able to preserve the knowledge in the databases to make them an effective component of knowledge-aware decision support systems; 3) it should try to strike a balance between the conflicting requirements of database owners, who require soft usability constraints, and database recipients who want tight usability constraints that ensure minimum distortions in the data; and 4) last but not least, it should not require that a database owner defines usability constraints for each type of application and every recipient separately. The major contribution of this paper is a robust and efficient watermarking scheme for relational databases that is able to meet all above-mentioned four challenges. The results of our experiments prove that the proposed scheme achieves 100 percent decoding accuracy even if only one watermarked row is left in the database.