Digital Fingerprint Algorithm For Vector Spatial Data

The rapid development of network technology and computer technology facilitates the acquisition and distribution of geospatial data,which makes geospatial data widely used in many fields of national economy and national defense construction,such as satellite navigation,urban and rural planning and construction,earthquake prevention and mitigation system.Geospatial data is the core of GIS applications.Vector spatial data with high-precision positioning is one of the basic data of geospatial data,which lays the foundation for the wide application of GIS and its multi-dimensional development for geospatial data.However,the illegal copy and distribution of vector spatial data,this brings damage to the interests of data owners,and also buries a hidden danger for the security of geographic information.Therefore,how to protect the digital copyright of vector spatial data and trace the source of illegal copy is an urgent problem in the field of geographic information security,which has attracted great attention of scholars.As a new technology for digital copyright protection,digital fingerprint can be used for copyright protection of digital products and tracking the illegal users.Digital fingerprint technology has been studied early in the research of copyright protection of multimedia data,especially in image and audio,but the research of digital fingerprint algorithm is less for vector spatial data.Based on the research of digital fingerprint in multimedia and the characteristics of vector spatial data,two digital fingerprint algorithms was proposed in this paper for copyright protection and conspirator tracking.The main contents of this paper are as follows:(1)Analysis of fingerprint coding scheme.The selection of fingerprint coding scheme is an indispensable part of digital fingerprint algorithm.Study the current common digital fingerprint coding scheme,its construction method,advantages and disadvantages,and analyze and compare the fingerprint length,detection complexity,anti-collusion attack capability and tracking ability and tracking ability of each coding.Based on this,lay the foundation for the selection of fingerprint coding scheme below.(2)To solve the problem of difficult tracking of illegal users and low coding efficiency after the distribution of vector spatial data,a fingerprint algorithm of vector spatial data based on GD-PBIBD is proposed.Firstly,the concept and construction characteristics of GD-PBIBD coding are introduced.Comparing the coding with BIBD code,the efficiency of the coding scheme is better than that of BIBD code.Considering the characteristics of vector spatial data in transform domain,the steps of fingerprint embedding and extraction are obtained,and the anti-collusion fingerprint algorithm is proposed.The feasibility of the combination of the steps of the algorithm is verified by an example.The research shows that the algorithm is feasible,which can ensure to track at least one conspirator and provide technical support for traitor tracking of vector spatial data.(3)In order to quickly track the conspirators of vector spatial data,a fingerprint algorithm based on the combination of area code and user code is proposed.In this paper,the idea of block coding is used to construct digital fingerprint,in which user code is GD-PBIBD code and I code is region code.Considering the characteristics of vector spatial data in space domain,the fingerprint algorithm for tracking the conspirators is proposed based on the fingerprint embedding and extraction steps mentioned above.The imperceptibility and robustness of the algorithm are verified by experiments.According to the collusion fingerprint,the area code can be located quickly and the detection rate of collusion can be improved.Research shows that the algorithm has good imperceptibility and robustness,and can ensure fast tracking of at least one conspirator.