A Robust Database Watermarking Scheme That Preserves Statistical Characteristics

Database watermarking can be used for copyright verification and leakage traceability, effectively protecting the security of the database. However, the existing watermarking schemes commonly embed watermarks by modifying the original data, which changes the statistical characteristics and affects the statistical analysis of the database. Therefore, this paper proposes SCPW, a Statistical Characteristics Preserving robust database Watermarking framework. First, we perform a theoretical analysis and propose a data modification scheme maintaining the statistical characteristics unchanged. Then, we establish the correspondence between the data and the watermarks that need to be embedded in it by grouping. Finally, the watermark message is embedded into the database through data verification and modification. Specifically, for data that needs to be watermarked, we first verify whether the potential watermark bits extracted from the data are the same as bits that need to be embedded. If they are the same, we regard this original data, usually a floating point number, as a “good number” and do not modify it. Otherwise, we modify the data until it becomes a “good number” using a data modification scheme that preserves the statistical characteristics proposed by the theoretical analysis. In addition, we also use the genetic algorithm to optimize the grouping results and increase the proportion of “good number”, thereby reducing the proportion of data that needs to be modified and further reducing distortion. To our best knowledge, SCPW is the first watermarking scheme that ensures the preservation of statistical characteristics, and the experimental results also prove its excellent ability to preserve statistical characteristics compared to existing schemes. Moreover, experiments also illustrate that our method is robust against a wide range of attacks. When under deletion attack (deletion rate = 90%), the bit error rate of watermark extraction is only 0.8%, which is more than 12% lower than the current best method.