An Improved Reversible Database Watermarking Method based on Histogram Shifting

Abstract

Database watermarking is typically employed to address the issues of data theft, illegal replication, and copyright infringement that may arise during the sharing of databases. Unfortunately, the existing methods often cause permanent distortion to the original data, and it is challenging to strike a balance between the watermark embedding capacity and data distortion. Therefore, this paper proposes a reversible database watermarking method based on histogram shifting, rhombus prediction, and double embedding with high capacity and low distortion, called RPDE-HSW. By utilizing the rhombus prediction, we respectively constructed two prediction error histograms in each subgroup and expanded the watermark capacity through the adoption of double-layer embedding and single-bin embedding 2 bits. A scrambling algorithm is used to make the attribute value distribution more discretized, resulting in a sparse distribution of the database histogram. Subsequently, we optimized the selection rules for the watermark embedding carrier, effectively eliminating the redundant distortion caused by histogram shifting. Experimental results demonstrate that the proposed method achieves smaller data distortion and higher watermark embedding capacity, outperforming some other state-of-the-art works, and does not affect the classification results and data mining.