The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 22, 2018
Filed:
May. 15, 2015
Mitsubishi Electric Corporation, Tokyo, JP;
Koichi Shimizu, Tokyo, JP;
Teruyoshi Yamaguchi, Tokyo, JP;
MITSUBISHI ELECTRIC CORPORATION, Tokyo, JP;
Abstract
The present invention relates to: a packet filtering apparatus that represents a rule set for packet filtering being a technique for preventing a cyber-attack, using a tree structure suitable for calculation of a logical expression, thereby improving processing efficiency; and a packet filtering method thereof. The packet filtering apparatus includes: a rule set containing a rule in which a condition and an action are associated with each other, and a Zero-Suppressed Binary Decision Diagram (ZDD) that represents a logical expression in which the condition of the rule is described using a logical variable; a packet analyzing unit to analyze a packet received from a network and extract collation information being a character string to be collated; and a filtering unit to collate the collation information extracted by the packet analyzing unit with the ZDD, execute the action associated with the condition that the collation information matches, and permit or deny communication of the packet.