US 6502135

An analysis of U.S. Patent 6,502,135 reveals a foundational patent in the field of secure network communications, which has been subject to litigation and has had its claims modified.

Patent Summary:

• Title: Agile network protocol for secure communications with assured system availability
• Assignee: The original assignee was Science Applications International Corp SAIC. The current assignee is listed as Virnetx Inc.
• Inventors: Edmund Colby Munger, Douglas Charles Schmidt, Robert Dunham Short, III, Victor Larson, and Michael Williamson
• Filing Date: February 15, 2000
• Issue Date: December 31, 2002
• Abstract: The patent describes a method for secure communication over a computer network where computer nodes use seemingly random Internet Protocol (IP) source and destination addresses. Data packets that match criteria defined by a moving window of valid addresses are accepted for further processing, while those that do not are rejected. The system also includes features such as a load balancer to distribute packets across different transmission paths, a DNS proxy server for transparently creating a virtual private network (VPN), a bandwidth management feature to prevent denial-of-service attacks, a traffic limiter, and a signaling synchronizer.

Plain-Language Overview of Independent Claims:

A review of the patent documentation indicates that some claims were subject to Inter Partes Review and have been changed or canceled as of March 4, 2024. The following is a plain-language interpretation of the original independent claims.

• Claim 1: This claim outlines a method for two computers to communicate securely over a network. It involves establishing a secure communication link, which is a virtual private network (VPN). This VPN is created by inserting data values into each data packet that change in a pseudo-random way.

• Claim 7: This claim focuses on creating a secure communication link between two computers on a network. A software module on the first computer requests a secure link with the second computer. If the first computer doesn't have the necessary secure communication software, it downloads it from a predetermined network address. Once the software is in place, it establishes a VPN link where data packets contain values that vary pseudo-randomly.

• Claim 12: This claim describes a method for transparently creating a secure communication link. When a user on a first computer tries to access a domain name, a proxy on that computer intercepts the request. It then determines if a secure link is needed. If so, a VPN is established where data packets include values that change in a pseudo-random sequence.

It is important to note that searches of the CAFC 2026 dockets did not yield specific results for U.S. Patent 6,502,135. However, this does not definitively mean there is no ongoing litigation, as docketing information can change.