MUSE: An Efficient and Accurate Verifiable Privacy-Preserving Multikeyword Text Search over Encrypted Cloud Data

Algorithm 1

.

Input: the document set with the respective file description and

document vector

Output: the HAC-tree

Variables:

CPNS—a set variable for storing the currently processing tree nodes

NGNS—a set variable for storing the newly generated tree nodes

Procedures:

(1) FOR EACH    DO

(2) Construct a new leaf node for documents where ,  ,  ,  

and ;

(3) Add into CPNS;

(4) END FOR

(5) WHILE    DO

(6) WHILE    DO

(7) ; //find a pair of nodes which have the maximum relevance score

(8) Construct a new node u as the parent of and   where  ,  ,  ,  ,

,  ,  ;

(9) Add into NGNS and delete and from CPNS;

(10)END WHILE

(11)IF    THEN

(12)Merge NGNS into CPNS and then clear NGNS;

(13)END IF

(14) END WHILE

(15) RETURN  the only node left in CPNS which is the root of the HAC-tree ;