Private information retrieval (PIR) LPPMs provide location privacy by mapping the spatial context to provide a private way to query a service without releasing any location information that could be obtained by third parties.
PIR-based methods can be classified as cryptography-based or hardware-based, according to [9]. Hardware-based methods use a special kind of secure coprocessor (SC) that acts as securely protected spaces in which the PIR query is processed in a non-decipherable way, as in [10]. Cryptography-based techniques only use logic resources, and do not require a special physical disposition on either the server or client-side.
In [10], the authors present a hybrid technique that uses a cloaking method through various-size grid Hilbert curves to limit the search domain of a generic cryptography-based PIR algorithm...
