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

Algorithm 4

SSDC.

Require:  EW has two encrypted squared distances along with their corresponding encrypted secrets, i.e.,

       , while AW holds secret key , where ,

       , , .

 () EW:

   (a) Generate a random number , two non-zero random numbers ;

   (b) Compute ;

   (c) Compute ;

   (d) if then

    (i) Compute ;

    (ii) Compute ;

   (e) else

    (i) Compute ;

    (ii) Compute ;

   (f) Send to AW;

 () AW:

   (a) Decrypt , for ;

   (b) Compute ;

   (c) if then

    (i) Compute ;

   (d) else if then

    (i) Compute ;

   (e) Encrypt ; Send to EW;

 () EW:

   (a) if then

    (i) Compute ;

    (ii) Compute ;

    (iii) Compute ;

   (b) else

    (i) Compute ;

    (ii) Compute ;

    (iii) Compute ;

 () return ;