Verifiable Location-Encrypted Spatial Aggregation Computing for Mobile Crowd Sensing

Algorithm 1

Location-encrypted spatial aggregation computing (LeSAC) protocol.

	Input: Common input
(i)	Paillier Encryption (Gen, Enc, Dec). Data provider ’s Pubic Key pubKey = n.
(ii)	Data provider ’s sensory data .
	Private input
(i)	Data provider ’s location , the request point location .
(ii)	The platform secretly holds the private key .
	Output: The aggregate value of the request location point
(1)	Geohash Boolean encod e //Block partitioning indexes building
(2)	For ; ; ;
(3)	do search neighbor regions of (left, right, up, down);
(4)	until ;//k is the threshold of the number of nerghbor points
(5)	EndFor;
(6)	For  = 1 to finally
(7)	For  = initial to
(8)
(9)
(10)	update add for each
(11)
(12)
(13)
(14)
(15)	Do loop until get sensing elements of all the unknown point
(16)	EndFor
(17)	EndFor
(18)	Platform output aggregation model results