Aiming to the privacy-preserving problem for moving-object retrieval services in social network

we propose a granular friend retrieval framework based on over-anonymity

called F-Seeker.Before outsourcing data

we adopt an enhanced anonymity strategy(

k

m

e

)-anonymity

which preserving user privacy from the curious retrieval service provider.In the processing of providing services

the service provider employs over-anonymity strategy based on visibility requirements to realize granular data access control.In addition

we encode data using Z-order address and the retrieval efficiency can be improved by pruning.Experimental results show that the proposed strategy can protect user privacy while the computation overhead does not inc

rease greatly.