非数值型数据的数据库水印算法研究

Study of Watermarking Nonnumeric Data in Relational Databases

分析了对非数值类型数据进行水印嵌入的特殊性,提出了基于非数值型数据水印的简单替换算法及其改进方法。为了减少水印嵌入对数据统计特性的改变,提出了一个统计特征控制算法,并设计了相关的实验,实验证明了算法的可用性和鲁棒性。

Most of current digital watermarking algorithms for relational databases can only embed digital watermark into numeric data. They seldom deal with nonnumeric data. There fore, research on digital watermarking algorithms that can embed watermark into non numeric data is very important, which will expand the application of digital watermarking. The particularity of embedding digital watermark into non-numeric data is analyzed. A simple substitution algorithm is firstly proposed, which can embed digital watermark into single attribute. Then an improving approach is proposed to extend the previous algorithm to multi ple attributes. On the purpose of making less change to the statistics of the data in watermarking, a statistic control algorithm is then proposed to improve the previous two algorithms. Finally, some relative experiments are designed to test the proposed algorithms. The experimental results show that the algorithms are effective and robust.