Privacy-Preserving -Means Clustering under Multiowner Setting in Distributed Cloud Environments

Algorithm 2

SA.

Require:  EW has and ; AW has the secret key

 () EW:

   (a) Generate random numbers: , s.t., for ;

   (b) Compute , and ;

   (c) Compute , and ;

   (d) Generate random numbers: , s.t., , ;

   (e) Compute , and ;

   (f) Compute , and ;

   (g) Compute , and ;

   (h) Send to AW;

 () AW:

   (a) Receive from AW;

   (b) Decrypt , for ;

   (c) Compute , , and ;

   (d) Encrypt , for ;

   (e) Send to EW;

 () EW:

   (a) Receive from EW;

   (b) Generate a random number: , s.t., ;

   (c) for to do

    (i) Compute ;

    (ii) Compute ;

   (d) Send to AW;

 () AW:

   (a) Receive from AW;

   (b) Decrypt , for ;

   (c) Compute ;

   (d) Encrypt ; Send to EW;

 () EW:

   (a) Receive from EW;

   (b) Compute ;

   (c) Compute ;

   (d) Compute ;