Homomorphic encryption-based position privacy querying method

Abstract

A homomorphic encryption-based position privacy querying method disclosed by the present invention comprises a cloud server, a data service provider and a plurality of mobile users. The data service provider SP partitions the areas in a map according to the intensity of the querying objects, then encrypts the querying objects in the partitions via a symmetric encryption algorithm, and encrypts thesymmetric secret keys via a homomorphic encryption algorithm, and finally stores all ciphertexts in the cloud server, thereby secretly saving the private keys of the homomorphic encryption. Users download the ciphertexts of the querying objects and the corresponding symmetric secret key ciphertexts from the cloud server according to the own positions, and further carry out the blind processing onthe symmetric secret key ciphertexts and transmit to the data service provider, and the data service provider transmits the decrypted blind plaintexts to the users, and finally, users decrypt the corresponding querying objects to obtain the final query results. According to the present invention, the position information of the users is not leaked during the whole process, thereby protecting theposition privacy.

Description

technical field [0001] The invention relates to the technical field of data encryption and location privacy protection, in particular to a query method suitable for protecting the location privacy of mobile users in a mobile internet network. Background technique [0002] In the application of the mobile Internet, location-based services have brought great convenience to people's life and work, but at the same time may cause the leakage of mobile user location information, thus bringing huge security risks. Therefore, with the wide application of LBS, the protection of mobile user privacy is essential. [0003] At present, the commonly used location privacy protection methods include pseudonym anonymity, location k anonymity, spatial anonymity and so on. [0004] (1) Pseudonym anonymity refers to hiding the real location of the real user through the location of a pseudonym user. The accuracy of the query is determined by the distance between the location of the pseudonym us...

AI Technical Summary

Problems solved by technology

[0004] (1) Pseudonym anonymity refers to hiding the real location of the real user through the location of a pseudonym user. The accuracy of the query is determined by the distance between the location of the pseudonym user and the location of the real user, which will reduce the accuracy of the query. It may also cause leakage of user information

[0005] (2) Location k anonymity mainly means that there are at least k users in a certain location area, and these k users cannot be distinguished by identity. Accurately identify real users

[0008] 1. In the existing location privacy protection, the location sent by the mobile user to the data service provider is a certain area, which increases the communication overhead

[0009] 2. The introduction of a third party to generate and manage keys in the existing location privacy protection may cause some privacy leaks of mobile users

[0010] 3. In the existing location privacy protection, data providers need to store a large amount of data

[0011] 4. In the existing location privacy, mobile users will not send the precise value of their location to the data service provider, which will reduce the accuracy of the query

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