A zero-watermarking algorithm for relational database copyright protection

To meet the demand of relation database copyright protection, a zero-watermarking algorithm is proposed. we introduce the idea of classification to database watermark working, giving a certain extent ease to the limit of data types and error bounds in database. This algorithm never changes the information of original object, but proves the databases' copyright belongs through the extraction of data's characteristics. It's good at hiding, and without original database in the recover progress, supports blind-checking of watermark information. Experimental result and analysis show the safety and robustness of the algorithm.