4. The system according to claim 1 , wherein the host processor searches the unencrypted index metadata for each sub-query to identify the sub-query indexes associated with each sub-query, the sub-query indexes being encrypted indexes that meet the criteria of each associated sub-query.
5. The system according to claim 4 , wherein the secure processor obtains the sub-query results as an intersection of the sub-query indexes associated with different fields when the query is associated with two or more fields.