A Study On Copyright Protection Of Vector Spatial Data Based On Zero-Watermark And Digital Fingerprint

With the development of Internet technology and the arrival of the big data wave,the sharing of vector spatial data has become more convenient,and it has been widely used in many fields such as surveying and mapping,satellite navigation,land and resources management,urban and rural planning and construction,and national defense military.The large-scale dissemination and application of vector spatial data has brought tremendous impetus to scientific research and economic construction.At the same time,the issue of piracy has become increasingly serious.It has seriously jeopardized the legitimate rights and interests of data production institute,and the illegal dissemination of high-precision vector spatial data will endanger national security.Therefore,there is an urgent need for a technology that can not only affect the normal use and reasonable sharing of vector spatial data,but also effectively protect vector spatial data copyright.Zero-watermarking technology has a natural advantage in copyright protection of vector spatial data because it does not modify the data.It can effectively solve the issue of copyright attribution of vector spatial data,but the meaning of vector data copyright protection should also include traitor tracking.Digital fingerprint technology as a powerful weapon for renegade tracking,can effectively solve this problem.In order to solve the above problems,this paper will apply the combination of zerowatermarking technology and digital fingerprinting technology to solve the problem of copyright determination and traitor tracking in vector spatial data,so as to effectively attack and deter users who illegally use and propagate vector spatial data.The two technologies have not only formed complementary functions,but also alleviated to a certain degree the serious deterioration of data quality brought about by excessive information embedding.Therefore,it is of great research significance and application value to study the application of both zero watermark and digital fingerprint in vector spatial data copyright protection.The main research contents and innovations are as follows:1.A zero watermarking algorithm for vector spatial data based on distribution centers is proposed.The algorithm considers the overall characteristics and local features of vector spatial data.After the data is divided into grids,the feature data is constructed using the average distance and distance between each grid point and its distribution center,and then the feature data and the scrambled watermark image are XORed to obtain the final zero-watermark image.The proposed algorithm can effectively resist random point shifting,panning,zooming,and cropping attacks.It can also be applied to point,line and polygon vector spatial data.When the data amount is small,the watermark detection effect is still ideal.2.A digital fingerprinting algorithm for vector spatial data based on I code and CFF code is proposed.Based on the analysis of the actual distribution process of vector spatial data and block-coded idea,block code encoding of I code and CFF code to establish a fingerprint database.And the fingerprint sequence is embedded into the vector spatial data DFT phase coefficients to be distributed using the QIM method to obtain the vector spatial data containing fingerprints.The fingerprint code constructed by this algorithm has a shorter code length while expanding user capacity,can effectively resist common collusion attacks,and correctly track at least one traitor.