Ontology-guided distortion control for robust-lossless database watermarking: Application to inpatient hospital stay records

In this paper, we propose a new semantic distortion control method for database watermarking. It is based on the identification of the semantic links that exist in-between attribute´s values in tuples by means of an ontology. Such a database distortion control provides the capability for any watermarking scheme to avoid incoherent records and consequently ensures: i) the normal interpretation of watermarked data, i.e. introducing a watermark semantically imperceptible; ii) prevent the identification by an attacker of watermarked tuples. The solution we present herein successfully combines this semantic distortion control method with a robust lossless watermarking scheme. Experimental results conducted on a medical database of more than one half million of inpatient hospital stay records also show a non-negligible gain of performance in terms of robustness and database distortion.