Abstract: In outsourced database scheme, since the database server, which is provided by the third part, is not in the trust domain, the data files may be pirated, and the data contents may be tampered with. A copyright protection system for outsourced database using information hiding technique was built, which was based on algorithms of database watermarking, as well as their corresponding protocols, and was combined with technologies of PKI, digital signature and USB Key. Compared with traditional solutions which of data encryption or digital signature, the copyright protection system for outsourced database based on information-hiding possesses advantages of less redundant capacity either for storage or for communication, better imperceptibility, and validation information harder to be removed.

Key words: Outsourced database, Information hiding, Digital watermarking, Copyright protection, USB Key