NTRU Implementation of Efficient Privacy-Preserving Location-Based Querying in VANET

Table 5

The proposed privacy-preserving location-based querying scheme.

Central Server	RSUs
Holds messages ,
.
Initialization phase
,
, G is a grid,
For all and  ,
,
,  ,
,
Put and all in RSUs.
	Receives and stores as well as all locally.
Local RSU	Driver
Holds and all as above.	Holds , ,
	.
Authentication and transaction phase
	Requests for service.
and sends it to the driver.
	,
	Completes the authentication as well as payment process with the central server.
	Receives from the central server and sends it to the RSU.
Verifies .
Retrieving phase
	Retrieves all from local RSU.
Executes the NTRU-based protocol with the driver.	Executes the NTRU-based protocol with the RSU and gets and .
	,
	,
	.