Location Privacy Protection Scheme for LBS in IoT

Algorithm 1

Geohash code generation algorithm.

Input: Position coordinates , code length

Output: Geohash code (CGh)

1. , ;

2. ; //The separate code length of longitude and latitude

3. ;

4. int , ; // is the number of latitudinal dichotomies, and is the number of longitude dichotomies

5. , ; //Dichotomizing the latitude and the longitude

6. while (latmid) //Convert longitude coordinates to binary

7. {

8.   char ;

9.   if

10.     ;

11.   else ;

12.   ;

13. }

14. while (lonmid) //Convert latitude coordinates to binary

15. {

16.   char ;

17.   if

18.     ;

19.   else ;

20.   ;

21. }

22. while //The longitude and latitude are combined, and the even bit is used to put the longitude, and the odd bit is used to put the latitude

23. {

24.   int ;

25.   char ;

26.   if

27.   {

28.     ;

29.     ;

30.     ;

31.   }

32.   else

33.   {

34.     ;

35.     ;

36.     ;

37.   }

38.   return ;

39. }

40. int ;

41. for (; )

42. {

43.   ; //Divide into groups of five digits

44.   ; //Map binary to Base32

45.   ;

46.   ;

47. }

48. return CGh; //Get Geohash code