Tampering Responsibility Identification Method Based On Digital Watermarking For Geographical Data

As a very important social resource and wealth, geographical data plays a significant role in scientific research and applications. At the same time, the reliability and integrity issues of geographical data are attracting people’s attention increasingly and the need of advanced technical means to solve those problems is more and more urgent, especially when tampering responsibility disputes occur between the producers and users of geographical data which are separated from each other.As a cutting-edge information security technology, digital watermarking technology is able to embed the watermarking information into the carrier data and make it an inseparable part of the data, so that not only the copyright protection and integrity authentication of the data but also the mutual authentication between the data producers and users can be achieved without any third party, which provides an effective technology support for the tampering responsibility identification of the geographical data. Based on the digital watermarking technology, the tampering responsibility identification of geographical data issue is discussed thoroughly in this paper, and furthermore taking the Digital Elevation Model (DEM) data for example, the principles and procedures of the algorithms involved in the specific issues are expounded in detail and the comprehensive experiments are analyzed. The main works are as follows:(1) The similarities and differences between the robust watermarking and fragile watermarking are comparatively analyzed so as to their respective technical features. Then special stress is laid on the basic theory and framework of fragile watermarking technology, the features of DEM data itself and its fragile watermarking are studied pertinently, too. Eventually, the evaluation indicators of DEM fragile watermarking are proposed.(2) Setting out from the tampering responsibility disputes between the producers and users of geographical data in practical applications, a possible solution is presented through in-depth analysis of the issues, then a common tampering responsibility identification method based on digital watermarking technology for geographical data is proposed. Taking DEM as the main research object, the key technologies of the method are studied.(3) Aiming at the features of the DEM data and DEM fragile watermarking, a fragile watermarking integrity authentication algorithm considering DEM terrain features is proposed. The algorithm fully utilizes the terrain features of DEM data and takes the local embedding strategy, which has effectively reduced the impact of data caused by the watermarking embedding while maintains the vulnerability of the watermarking algorithm on the global data and has a good security and suitability.(4) According to the issue that the existing fragile watermarking technology is able to authenticate the integrity but cannot identify the tampering responsibility of geographical data, a DEM integrity authentication algorithm using preventing re-embedded double watermarking is put forward by introducing the robust watermarking which is strongly robust on the basis of fragile watermarking. The algorithm is used to verify the feasibility of the responsibility identification method for geographical data tampering presented in this paper. The experimental results show that, on the one hand, the proposed algorithm can effectively prevent the watermarking being re-embedded and has a good validity of the integrity certification; on the other hand, the proposed method is able to practically solve the tampering responsibility identification problems between the geographical data producers and users.