In relational databases, embedding watermarks in integer data using traditional histogram shifting method has the problem of large data distortion. To solve this problem, a reversible database watermarking method without redundant shifting distortion is proposed, taking advantage of a large number of gaps in the integer histogram. This method embeds the watermark bit by bit on the basis of grouping. First, an integer data histogram is constructed with the absolute value of the prediction error of the data as a variable. Second, the positional relationship between each column and the gap in the histogram is analyzed to find out all the columns adjacent to the gap. Third, the highest column is selected as the embedded point. Finally, a watermark bit is embedded on the group by the histogram non-redundant shifting method. Experimental results show that compared with existing reversible database watermarking methods, such as genetic algorithm and histogram shift watermarking and histogram gap–based watermarking, the proposed method has no data distortion caused by the shifting redundant histogram columns after embedding watermarks on forest cover type data set and effectively reduces the data distortion rate after embedding watermarks.

中文翻译：

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一种基于非冗余移位直方图间隙的可逆数据库水印方法

在关系数据库中，使用传统的直方图移位方法在整数数据中嵌入水印存在数据失真大的问题。针对这一问题，利用整数直方图中的大量空白，提出了一种无冗余移位失真的可逆数据库水印方法。该方法在分组的基础上逐位嵌入水印。首先，以数据的预测误差的绝对值为变量构造整数数据直方图。其次，分析直方图中各列与间隙的位置关系，找出与间隙相邻的所有列。第三，选择最高的列作为嵌入点。最后，通过直方图非冗余移位方法在组上嵌入一个水印位。