| In recent years,the development of information technology in various industries such as the Internet and social platforms has led to an explosive growth of data in many fields,and data with geographic spatial locations has also increased rapidly.The era of spatial big data has arrived.Geospatial data has the characteristics of a wide variety,large amount of data,and fast generation speed.Traditional relational databases are difficult to deal with.However,the newly emerging distributed databases such as Hbase and Phoenix have the advantages of high performance and high reliability,but they do not provide Direct support for geospatial data storage and management.In addition,in order to reduce the cost of data storage hardware and data management services,some companies often store geospatial data on cloud platforms.In order to prevent the cloud platform from leaking data,users will encrypt the data before storing it on the cloud platform,and directly perform query operations based on the ciphertext,so that the privacy of the data is protected.However,there are only relational encrypted databases such as Crypt DB,and no non-relational encrypted databases have appeared,and Crypt DB does not support the encryption operation of 3D geospatial data.In response to the above problems,this thesis expands the three-dimensional spatial data based on the Phoenix database layer,designs and implements a three-dimensional encrypted database prototype system.The system supports main functions such as encrypted storage of three-dimensional spatial point data,ciphertext range query and KNN query,and meets the characteristics of data secure transmission,custom SQL statements,and has the advantages of ease of use and high reliability.The main contents of this thesis are as follows:(1)The design and realization of the query plan for the three-dimensional space encrypted data range.This thesis proposes two range query schemes for three-dimensional spatial encrypted data,namely STCode-OPE scheme and Fast Geo-SSW scheme.The STCode-OPE scheme first uses STCode encoding to index the three-dimensional spatial data,then uses the OPE encryption algorithm to encrypt the STCode value,and finally implements range query on the encrypted STCode value;the Fast Geo-SSW scheme first uses AES-CBC-The256 and SSW encryption algorithms encrypt the preprocessed three-dimensional spatial data,and then build the memory index of the encrypted data in the form of Key-Value,and finally enumerate the points in the range and implement the range query through the inner product operation.(2)Design and implementation of KNN query scheme for three-dimensional space encrypted data.This thesis converts the KNN query scheme of the three-dimensional space encrypted data into a cuboid range query,expands the cylindrical range of the KNN query,calculates the minimum external cuboid of the query range,and then calls the above range query scheme to realize the KNN query function.(3)Design and implementation of custom SQL statement interception and encryption rewriting schemes.In order to enhance the ease of use of the system,this article supports a custom SQL statement syntax to query the three-dimensional space encrypted data.By distributing the intercepted custom SQL statement to the corresponding Handler processor,the SQL statement is parsed,encrypted and rewritten in the Handler processor,and finally the rewritten standard SQL is sent to the Executor executor.Finally,for the designed three-dimensional space encryption database prototype system,this thesis built the system in the VMare virtual machine as an experimental environment,and based on the data set provided by GDELT,through multiple experiments the data entry function and range query function of the system The KNN query function and the efficiency of the query plan are evaluated.The experimental results show that the three-dimensional spatial encryption database prototype system has the advantages of high query efficiency,good security performance,etc.,and has good usability. |
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