Blind Watermarking Method for Anonymized Data

The secondary use of data in consideration of individual privacy has been gaining attention. Data anonymization needs to be applied to enable both secondary use and privacy protection. In distributing anonymized data, there is a concern that data users might re-distribute the data to a third party without permission. To tackle this issue, a watermarking technique that correlates data users (IDs) with anonymized data has been studied. In existing studies, a non-blind detection method has been employed to obtain the IDs; however, the problem is the use of original data in the detection, which deteriorates the applicability. In this paper, a watermarking technique in combination with a blind detection method is proposed. We evaluate and compare the proposed watermarking method with an existing non-blind method in terms of information loss, tolerance against attacks, and the processing time of watermarking and detection.