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

Algorithm 2

.

Input:   is the root of the current searched sub-tree,  is the vector of a query and k is the number of requested documents.

Output: the top- documents

Variables:

—a local variable for tree node;

—a global variable for storing a relevance score threshold which is initialized that ;

—a list variable for storing the leaf node containing candidate result documents which are initialized that .

When NCP-DFS is finished,    contains the leaf nodes which stores the top- result documents.

Procedures:

(1) ;

(2) IF    is a leaf node THEN

(3) IF    THEN

(4) Add into ;

(5) ELSE IF    THEN

(6) Add into ;

(7); //obtain the th relevance score in as a threshold

(8) ELSE

(9) IF    THEN

(10) ;

(11) Delete from and add into ;

(12) ;

(13) ;

(14) END IF

(15) END IF

(16) ELSE  //if is the internal node

(17) IF    THEN

(18) ;

(19) ;

(20) END IF

(21) END IF