PACKET DATA COMPARATOR AS WELL AS VIRUS FILTER, VIRUS CHECKER AND NETWORK SYSTEM USING THE SAME

摘要

It is an object of the present invention to realize a network system which can quickly detect a virus and tends not to be a new cause of vulnerability. A packet data comparator disclosed by the present invention branches inputted packet data into three branches, and includes an additional pattern matching unit which compares the branched packet data with a part of stored data and performs matching with collation patterns stored in a rewritable storage area, a fixed pattern matching unit which compares the branched packet data with the part of the stored data and performs the matching with a logical operation which has been configured with known collation patterns, a notification packet matching unit which compares the branched packet data with the part of the stored data and finds a notification packet, and an identity detection aggregation unit which aggregates results from the respective matching units. Moreover, a virus filter is configured by using the packet data comparator, a virus checker which can be updated through a network is configured by using the above described virus filter, and a secure network system is realized by using the above described virus checker.