基于汉字字段的关系数据库数字水印研究

提出了一种实用的基于汉字字段的关系数据库数字水印新方案。通过主键、用户密钥集合和水印嵌入间距确定目标属性值。根据定义的规则，计算比较属性值和水印的特征值并将不同位作为水印嵌入位。通过语义分析给出属性域中某个最相关的非上下结构的汉字，嵌入水印的过程就是编辑(插入/删除)该汉字。嵌入的水印具有不可见性，并且不影响数据库的可用性，可实现盲提取。该方案对插入、删除、修改数据库记录以及删除数据库字段等常见数据库更新具有较好的鲁棒性。

Research on Watermarking Relational Database Based on Character Field

An innovative practical watermarking scheme for relational database based on character field was proposed in this paper. Identifying the target attribute values through the primary key, set of user keys and the span of watermark.Calculating the characteristics of attribute values and the watermark according to the defined rules and choosing those different bits as watermark bits. Semantic analysis gives a character, which is non-down structure and one of the most relevant attributes in the domain,and watermark embedding is the process of editing(insert/delete) the character. The embedded watermark is invisible and does not affect the availability of the database, and enables the blind extraction.The proposed scheme can achieve good excellent robustness to common database update such as insert, delete, modify and delete database fields.