US 6795918

US Patent 6,795,918: Service Level Computer Security

Title: Service level computer security

Current Assignee: WETRO LAN LLC (as of 2015-01-22)

Inventor(s): Steven T. Trolan

Filing Date: 2000-03-07

Issue Date: 2004-09-21

Abstract: The patent describes novel apparatus and methods for filtering data packets by providing non-user configurable authorization data. The invention aims to offer an efficient, quick, secure, and simple-to-implement technique for computer communication security, partly by utilizing service-level filtering of data packets.

Plain-Language Overview of Independent Claims:

• Independent Claim 1: Method for filtering data packets
  This claim describes a method that involves receiving a data packet containing source, destination, and protocol information. This information is extracted and provided to a decision block that is non-user configurable and "substantially free from user adjustment." This decision block contains information about which services are authorized based on the extracted data. If the information indicates an unauthorized service, the data packet is dropped; otherwise, it is permitted to pass through. The protocol information specifically includes transport types.

• Independent Claim 10: Computer security apparatus (unidirectional)
  This claim outlines a hardware apparatus designed for computer security. It includes a first communication interface connected to a public network (e.g., the Internet) to receive data packets. A packet analyzer is coupled to this interface, containing storage devices for communication protocol, source port, and destination port information extracted from a data packet. A non-user configurable lookup table (LUT) device, coupled to these storage devices, determines if the packet is authorized to pass. If authorized, it's sent to a private network via a second communication interface. This apparatus only allows data packets for a "selected group of Internet services" to be transferred to the private network, and the lookup table cannot be configured by a user. The communication protocol information also includes transport types.

• Independent Claim 21: Computer security apparatus (bidirectional)
  Similar to Claim 10, this claim describes a computer security apparatus with first and second communication interfaces for public and private networks, respectively, and a packet analyzer with protocol, source port, destination port storage, and a non-user configurable lookup table. The key distinction is that this apparatus is configured for bidirectional filtering. It receives data from the public network to send to the private network, and also receives data from the private network to send to the public network, applying the same service-level filtering with its non-user configurable lookup table in both directions.

• Independent Claim 25: Service level computer security apparatus (means-plus-function)
  This claim is written in means-plus-function format, describing a service-level computer security apparatus through its functional components. It includes "means for receiving," "means for extracting," "means for providing" (to a non-user configurable decision block with authorization information), "means for dropping" unauthorized packets, and "means for permitting" authorized packets. As with Claim 1, the protocol information includes transport types.

• Independent Claim 26: Method for converting an unsecured digital transmission line into a secured digital transmission line
  This claim describes a method for securing a digital transmission line by inserting a specific computer security apparatus into an unsecured network connection. The digital data can come from transmission mediums like cable modem or xDSL. The inserted apparatus is detailed, including its first and second communication interfaces, packet analyzer with protocol, source port, and destination port storage, and a non-user configurable lookup table device that determines authorization based on packet data. This apparatus ensures only a selected group of Internet services can be transferred, with the lookup table being non-configurable by a computer user.

Litigation Information:
A search of CAFC 2026 dockets for patent number 6795918 did not yield any specific litigation cases for the year 2026. Given the patent's "Expired - Fee Related" status as of March 7, 2020, (according to Google Patents data provided in the prompt), new litigation related to infringement is unlikely.