Order-Revealing Encryption Scheme with Comparison Token for Cloud Computing
Algorithm 2
Tree search.
(i)
Input:
(ii)
encrypted PORE tree:
(iii)
search token: = ( )
(iv)
Output:
(v)
encrypted results:
(1)
CSP proceeds the search algorithm twice, once for to find the leftmost leaf node and once for to find the rightmost leaf node;
(2)
fordo
(3)
CSP checks whether by checking whether there exists a row in matrix such that the positions of are equal to 1;
(4)
Afterwards, CSP finds the largest value satisfying and updates its corresponding child as the new value for ;
(5)
end for
(6)
CSP obtains the leftmost leaf node and the rightmost leaf node;
(7)
Finally, CSP returns results which include data items in leaf nodes between the two leaf nodes, in the leftmost leaf node satisfying and in the rightmost leaf node satisfying .
