Nonexposure Accurate Location 𝐾-Anonymity Algorithm in LBS

Algorithm 2

Random ASR.

(1)  function random ASR (𝑘, 𝐴_min, ID_now(𝑋,𝑌))

(2)       int random = new Random (10); //new an integer and set its value randomly from 1 to 10.

(3--11)     // “line 3 to line 11” are the same to “line 2 to line 10” in the Algorithm 1.

(12)    if (random > rnd ) {   //rnd is integer which is set by the system.

(13)     Adds the grid-area which has the highest QoS into 𝑆 until the total users in 𝑆 is not less than 𝑘;

(14)     // the QoS of the grid-area can be calculated by Formula (3).

(15)    break;

(16)  } //end if

(17)   else  {

(18)    Adds the grid-area into 𝑆 by randomly until the total users in 𝑆 is not less than 𝑘;

(19)     break;

(20)  }     //end else

(21--25)      // “line 21 to line 25” are the same to “line 14 to line 18” in the Algorithm 1.

(26)      if (random > rnd ) {

(27)      adds the grid-area which has the highest QoS into 𝑆 until the total square measure of 𝑆

(28)      is not less than 𝐴_min; // the QoS of the grid-area can be calculated by Formula (2).

(29)       break;

(30)  } //end if

(31)   else  {

(32)     Adds the grid-area into 𝑆 by randomly until the total square measure of 𝑆 is not less than 𝐴_min;

(33)     break;

(34)      }    //end else

(35--38)     // “line 35 to line 38” are the same to “line 21 to line 24” in the Algorithm 1.