A New Group Location Privacy-Preserving Method Based on Distributed Architecture in LBS

Table 2

Characteristics comparison.

Scheme	[3]	[4]	[5]	[6]	Ours
Method	Distance sum	Center location	Center location	Center location	Center location
Network resources occupied	Low	Low	Low	High	Low
The size of the service result set
Resistance against the collusion attack between SP and users			or ( with or without the special proxy user)
Controllability of the location privacy protection	Fine-granularity	Coarse-granularity	Coarse-granularity	Coarse-granularity	Fine-granularity
Communication mode	Ring-unicast	Ring-unicast	Star-unicast	Group-broadcast	Star-unicast
User state	Static	Static/dynamic	Static/dynamic	Static	Static/dynamic