Digital watermarking algorithm of relational database

The invention relates to a digital watermarking algorithm of a relational database. The threat problems of copyright protection, confidentiality and privacy of content and authenticity and integrity of data faced by the security of the existing database are solved. The method comprises the following steps: 1, preprocessing data; 2, converting a watermark plaintext into a binary sequence by using aprivate key of a database copyright owner; 3, respectively executing a watermark embedding program by taking each attribute value as a non-numerical attribute column of the natural language as a unit; 4, publishing the database table embedded with the watermark; 5, when a copyright dispute occurs, carrying out watermark extraction work on the database table with the copyright dispute, and using the watermark as an effective proof of copyright affiliation; and 6, completing watermark extraction according to the personal private key of the database owner, the key corresponding to the attributecolumn, the existence of t