KLPPS: A k-Anonymous Location Privacy Protection Scheme via Dummies and Stackelberg Game
Algorithm 1
A dummy location selection algorithm based on location semantic and physical distance.
Input:: user’s real location
: user’s privacy requirement
: map information in current Wi-Fi AP : location semantic tree : location query probability;
Output:: dummy location set;
(1)
Divide the as the sample space into grids;
(2)
Generate semantic distance matric according to the and geographic distance matrix according to the and probability distance matric according to the respectively
(3)
According to and , choose the locations with , which are closest to , and then a offset location set consisting of the locations and has been generated;
(4)
Randomly choose a location from as offset location
(5)
Generate a dummy location candidate set for all locations in the whole
grid space;
(6)
(7)
Remove from ;
(8)
whiledo
(9)
ifthen
(10)
anonymity failed;
(11)
else
(12)
;;
(13)
for eachindo
(14)
ifthen
(15)
anonymity failed;
(16)
go back to line 13;
(17)
else
(18)
(19)
compute the maximum according to , and , which is recorded with , and then assign the corresponding to
