A Hybrid Watermarking Scheme for Relational Databases Copyright Protection and Tamper Proofing

To date, database watermarking schemes are classified to be either robust or fragile depending on whether they are designed for copyright protection or data integrity checking. In this paper, we propose a novel approach that combines robust and fragile watermarking for ownership proofing and tamper detection and localization of relational data. The scheme first securely embeds a multi-bits robust watermark into the database relation. For fragile watermark embedding, the robustly marked relation is partitioned into groups. Then, a watermark is computed and inserted in each group independently in a way that preserves the robustness and the reliability of the robust component. All watermarks are securely detected without requiring access to the original database relation. Through rigorous theoretical analysis, we demonstrate that our proposed hybrid approach is secure against common database attacks. Furthermore, our experiments conducted on real life data showed that the proposed method can be effectively used in real world applications.