The Research On The Relational Database Watermarking Based On The Virtual Primary Key

The digital watermarking is one of the information security technologies to protect the copyright of digital products. With the development of the internet techology, the database has been widely applied on the network, and the copyright protection of database has been caught increasing attention by both the academia and business. Consequently, to protect the database security, the digital watermarking technology is applied to the database.At present, the database watermarking is developing, the algorithm robustness need to be improved. The traditional algorithm of the database watermarking, which regards primary key as the marked benchmark both for embedding and extracting, can not resist the primary key attack as the watermarking may earily erased. Based on the existing database watermarking research, this paper studied the relational database watermarking algorithm on the virtual primary key to resist the primary key attack and improve the algorithm robustness.A relational database watermarking algorithm based on the virtual primary key was proposed in this paper. The virtual primary key was regarded as the marked benchmark for the relational database instead of the real primary key, and error was introduced in the database specified least significant bit by embeding a binary image watermarking. The choosing virtual primary key algorithm was given, and the problem of embedding with duplicate virtual primary key values was solved as well. Then the (7, 4) hamming code was combined with large numbers voting to enhance the watermark robustness. With the algorithm, a virtual primary key-based watermarking system was built in this paper to implement watermark embedding and extraction operations in databases.Based on the single virtual primary key algorithm, this paper intrduced the thought of RAID, proposed a redundant virtual primary key database watermarking algorithm.The algorithm solved the defects of the algorithm of single virtual primary key that if the virtual primary key was deleted, the watermarking can't be restored. Even if only one virtual primary key was left after attack, the watermarking will be restored effectively, which enhance the watermark robustness. At the same time, watermarking information consisted of both the copyright information and the distribution information. Therefore from the recovery of the watermarking, the source of piracy and the copyright information can be both attained.The algorithm of this paper solved the problem that the traditional database watermarking can't response the primary key attack and the poor robustness.The experimental results and the theoretical analysis showed that both algorithms have strong robustness, which are extremely effective watermarking schemes, and have certain significance on digital watermarking technology in theoretical development and practical application.