A method is provided for allowing a database search that prevents an owner of
the
database or someone intercepting the database search in the network from knowing
the contents of the query, without requiring any particular processing on the part
of the database. Client 20 accesses database server 10 which stores
sequence patterns and inquires whether the sequence patterns stored in the database
server 10 exist in a predetermined sequence. Client 20 comprises
sequence processing section 21 for dividing a search sequence subjected
to search to create multiple subsequences; and query issuing section 22 for
issuing a query to database server 10 using the created multiple subsequences
individually as a query sequence.
