Marcus Ranum

Marcus Ranum is a computer security expert. He worked for Digital Equipment where he implemented the first commercially available firewall product, SEAL. His later work has included the TIS firewall toolkit and the Gauntlet firewall. He founded the company Network Flight Recorder and designed their main product, an intrusion detection system.

He has a web site; well-known pages there include a One-time pad FAQ and one on the ultimate firewall.