基于用户约束的关系数据库水印方法

针对现有水印算法的不足，提出了在数值型属性最低有效位(LSB)嵌入水印信息的一种新方法。算法先筛选出可以嵌入水印信息的属性，将它们划分为若干个等大的子集，然后依据数据库所有者定义的约束对这些子集进一步筛选，以筛选后的每个子集为单位嵌入水印信息0或1。水印检测算法依据的是中心极限定理，实现了水印信息的准确检测。SQL Server仿真实验验证了此方法在现实应用中的有效性。

Relational database watermark method based on user restraint

A new method that digital watermarking information was embedded in numerical attribute's Least Significant Bit （LSB） was put forward in view of the existing watermark algorithm's insufficiency. After sieving attributes that could embed watermarking information and dividing these attributes into some equal subsets that would be further sieved based on the binding defined by the database owner， watermark 0 or 1 was embedded into each sieved subset. The watermark detection algorithm based on the central limit theorem can test watermarking information accurately. In the end， the simulation experiment using SQL Server verified the validity of algorithm in practical application.