A Database Watermarking Technique Based On Independent Component Analysis

Watermarking technique used as a method of information hiding has been ripely developed and widely used, which basical idea is a process of embedding privacy information into various multimedia data, to offer copyright protection. Currently digital watermark technology mainly concentrates on the multimedia data (e.g., image, audio, and video) and great progress has been made.As the network fleetly developed, more and more attention is focusing on the safety of database. Embedding ownership's information as watermarking into relational database for its copyright protection has been a new heated research on database security. Database watermarking, which embeds implicit and un-removable marks in database through the method of signal processing, reaches the aim of protecting the database security without damaging the content and the availability of database.What the technology of database watermarking can provide are the abilities of proving the ownership of the database, verifying the integrity of the data contents and presenting the electronic evidences for accusing the piracy and attack to the database, rather than constraining regular data accessing. Meanwhile, database watermarking can work conjointly with cryptography to reinforce database security.How to insert digital watermark into the relational database has become an urgent problem that should be resolved. At present, little has been done to secure proof of copyrights over relational database, the domestic and foreign researches have only carried out a tentative study. However,multimedia oriented watermarking technique can't be used on database directly for special structure of database. This paper does research on how to improve the robustness of watermarking algorithm oriented to relational database. the contributions of this paper are as follows:Database is characterized by its large capacity and the fact that the data involved are largely numbers. According to these characteristics, a database watermarking method is proposed which is based on Independent Component Analysis (ICA). First, adopting one way hash function as the way of marked calculation, the paper define the tuple to be marked according to the secure key , tuple key value and the ratio of tuples to be marked provided by customers. Then, single dimensional watermarking vector and data in equally long marked database are used to mix matrix. The mixed watermarking signal produced after N times of rolling is embedded into the database. The extraction of watermarking is fulfilled through secret key and the watermarking-carrying information obtained from database. And ICA is used to separate matrix and attain the final watermarking information. The watermarking information rolling is kept independent from the original database information, realizing embedding of watermarking information with little change of the carrier. Also, the ICA method is employed to extract watermarking image. The ICA ratio method adopted can better solve the influences from uncertainties of the arrangement order. The results of the experiment show that the proposed algorithm has a good testing effect.