US 5835726

Patent Overview: US 5,835,726

Title: System for securing the flow of and selectively modifying packets in a computer network

Patent number: US 5,835,726 A
Application number: US 08/664,839
Assignee: Check Point Software Technologies Ltd. (original and current, per listing)
Inventors: Gil Shwed, Shlomo Kramer, Nir Zuk, Gil Dogon, Ehud Ben-Reuven
Priority date: 1993-12-15 (claimed from US 08/168,041 / patent US5606668A)
Filing date: 1996-06-17
Publication (grant) date: 1998-11-10
Anticipated expiration: 2013-12-15; legal status listed as "Expired - Lifetime"
Source: https://patents.google.com/patent/US5835726/en

Purpose (per the supplied text): The application addresses the tension between connectivity and security in computer networks. It describes an "easily alterable or expandable method for computer network security which controls information flow on the network from/to external and internal destinations." It frames packet filtering as a way to allow connectivity while controlling traffic and preventing illegal communication attempts, both within single networks and between connected networks. The excerpt also notes a stated disadvantage of virtual private networks (VPNs)—that insecure public segments make them insecure—and contrasts packet filtering with the costly, inflexible approach of manually tailoring operating-system code at strategic network points.

Plain-language scope (from the excerpt): The invention concerns securing data-packet flow on a computer network and selectively modifying packets, using packet filtering that can be altered or expanded. Classification codes place it in network security for separating internal from external traffic (firewalls), filtering policies and rule management, virtual private networks, and verification of received information (message integrity and data source).

What the excerpt does not establish:

• The full text of the claims or the precise claimed scope. The extract contains indexed keyword counts (e.g., "filtration," "modification," "inspection," "verification") but not claim language, so no specific claim limitations can be cited.
• The detailed architecture or method steps, figures, or the specific packet-modification mechanisms.
• Any prior-art analysis or comparison beyond the general statements quoted above.
• Litigation, ownership changes, or validity conclusions.

Because only an excerpt was supplied, the above is limited to what the text states; omitted passages may add scope or detail not captured here.