Research And Implementation On Reversible Watermarking Of Database Based On PSO Algorithm

With the development of big data,cloud computing technology,and extensive use of database technology,massive data is transmitted and stored through the Internet.This database-borne information is facing issues such as illegal copying and piracy.As an effective tool to protect data copyright in database,database watermarking technology is playing its role.Based on the characteristics of relational data with low redundancy and high dispersion,this paper proposes a reversible relation database watermark based on discrete particle swarm optimization algorithm(DPSO).Firstly,the copyright image is binarized and scrambled to generate a binary bit sequence which to guide the embedding of the watermark.The selected database is pre-blocked then,the tuple primary key in each data block is hashed.According to the coordinate index of the attribute column and the number of tuples of each data block,a certain percentage of the point set in the data block is selected to be used as a watermark embedding part of a data block.Then,a discrete particle swarm optimization algorithm is used on each data block to encode a particle with a set of points to be embedded,and a fitness function is used to determine the quality of a particle.A random watermark is assigned to the data block during the initialization phase of the population.After the maximum number of iterations is over,the set of to-be-inserted points represented by the global optimal particles is taken as the position to be embedded.In the watermark embedding stage,the search algorithm searches for the optimal position to be embedded,saves the intermediate data in the embedding process,and is used as a watermark extraction and data recovery.Secondly,in order to verify the robustness of the database watermark,the embedding of a successful database with different intensity simulation attacks has achieved the purpose of destroying the carrier data.Finally,the watermark extraction algorithm extracts the watermark information and recovers the original data and copyright information.In order to verify the effectiveness and practicability of the algorithm,this paper designed and developed a database watermarking simulation system based on Java Web framework.Different watermark parameters can be selected in the system interface to verify the invisibility and robustness of the database watermark.It provides a relatively intuitive experimental platform for the study of subsequent database watermarks.