A New Relational Database Watermarking Algorithm Based on Chaos
This paper proposed a new database watermarking algorithm based on a numerical attribute of database. Firstly, the copyright image was encrypted by a chaotic system to produce a binary sequence as the watermark signal. Then it used two hash functions to realize the watermark embedding. The first hash value was calculated by using the connection value of the key and the primary key. Then it filtered out the tuples whose corresponding hash value was even. The second double-hash value was calculated by using the connection of the key and the first hash value, which was used to label tuples and partition tuples. The first hash value was used as a control signal to adjust the parity of the candidate attribute bit when the watermark was embedded. Theoretical analysis and experimental results indicate that the algorithm reduces the amount of embedding watermark and improves the robustness and security of the watermark.