A robust multiple watermarking technique for information recovery

Digital databases serve as the vehicles for compiling, disseminating and utilizing all forms of information that are pivotal for societal development. A major challenge that needs to be tackled is to recover crucial information that may be lost due to malicious attacks on database integrity. In the domain of digital watermarking, past research has focused on robust watermarking for establishing database ownership and fragile watermarking for tamper detection. In this paper, we propose a new technique for multiple watermarking of relational databases that provides a unified solution to two major security concerns; ownership identification and information recovery. In order to resolve ownership conflicts a secure watermark is embedded using a secret key known only to the database owner. Another watermark encapsulates granular information on user-specified crucial attributes in a manner such that the perturbed or lost data can be regenerated conveniently later. Theoretical analysis shows that the probability of successful regeneration of tampered/lost data improves dramatically as we increase the number of candidate attributes for embedding the watermark. We experimentally verify that the proposed technique is robust enough to extract the watermark accurately even after 100% tuple addition or alteration and after 98% tuple deletion.