Research Article

A Dynamic Privacy Protection Mechanism for Spatiotemporal Crowdsourcing

Algorithm 1

Static publishing anonymity protection based on k-anonymity.
Input: k-anonymous parameter k, the actual spatiotemporal dataset A from participants
Output: aggregation result U, buffer pool dataset B
(1) Calculate the global centroid of A by equation (3)
(2),
(3)while do
(4)  
(5)  
(6)  ,
(7)  for to do
(8)   Update the centroid of by equation (3)
(9)   
(10)   ,
(11)  end for
(12)  whiledo
(13)   Calculate the average distance of by equation (4)
(14)   
(15)   ifthen
(16)    ,
(17)    Update the centroid of by equation (3)
(18)   end if
(19)  end while
(20)  ,
(21)end while
(22)B = A
(23)return U, B