Batching Location Cloaking Techniques for Location Privacy and Safety Protection

Algorithm 2

Bottom-up cloaking batching algorithm (BU).

	Data: set U
	Result: A set of cloaking regions for every user u in U satisfying its respective and
(1)	chooses a user with the highest K from U (denoted as ). If there are many of them, chooses one with the highest θ in U;
(2)	call Algorithm 1 (l, );
(3)	repeat
(4)	if () then
(5)	for do
(6)	if and ;
(7)	Remove u from U only if was set as ;
(8)	end
(9)	end
(10)	c from with a probability inversely distance (, ) ’s occupancy;
(11)	;
(12)	until ;