STQ-SCS: An Efficient and Secure Scheme for Fine-Grained Spatial-Temporal Top- Query in Fog-Based Mobile Sensor-Cloud Systems

Table 1

Notations and their meanings.

Notations	Meanings
	The sensor node whose ID is
	Total number of sensor nodes in one MWSN
	The epoch
	Total number of target locations of in
	The target location of during
	Total data item numbers of generated at in
	Total number of qualified Top- data items generated by at in
	A spatial-temporal Top- query
	The query result of
	The ID of
	The ID of an MWSN
	The queried region in an MWSN whose ID is
	The pairwise key which is distributed to sensor node
	The data report generated by in
	Symmetric encrypting operation with based on [34]
	Encrypting operation based on the OPE encryption scheme [35]
	The processed result of
	Total number of the queried locations encrypted in
	Total number of the sensed data items encrypted in
	Set of the qualified Top- data items extracted from