Research Article
A Privacy-Preserving Location-Based System for Continuous Spatial Queries
Algorithm 2
Anonymizer’s query processing.
Input: query issuer’s current location and destination, CR chosen by the query issuer, and (number of clients for location | anonymity), content of the query | Output: K-anonymous clients in a minimum CR, member clients | () Check the CR chosen by the query issuer using the anonymizer; | () Calculate the minimum distance (, , , = null); | () if then return 0 | () | () while | () | () ; | () ; | () if (); | () continuous; | () else end if; | () end while; | () if (periodically measure the CRs of dist(, ) and sort the CRs in ascending order (i.e., from the smallest to the largest)) | () return ; (th is from 1 to ) |
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