Marcus is a semi-retired independent consultant and technology advisor to start-ups and large enterprises. He is recognized as an innovator in firewall technology and the implementer of the first commercial firewall product. Marcus’s work has been cited in at least 15 published U.S. patents in addition to computer and network security articles and books.

• Log Analysis
• Metrics and Metrics Program Design
• Security System Design
• Vulnerability Management
• Segmentation and Enclaves

• Designer of firewall products such as DEC SEAL, TIS firewall toolkit, Gauntlet firewall, and NFR's Network Flight intrusion detection system
• Builder of the first internet email service for the whitehouse.gov domain
• Winner of the ISSA Fellowship and inducted into ISSA’s all of fame
• Winner of the Techno-Security Professional of the Year award
• Co-Author of Host Intrusion Monitoring Using Osiris and Samhain (2005)
• Author of The Myth of Homeland Security (2003)
• Co-Author of Web Security Sourcebook (1997)
• Former Instructor for SANS Institute
• Former CSO at Tenable Network Security, an information security monitoring company
• Former Founder, CEO, and CTO of Network Flight Recorder
• Former Chief Scientist at Trusted Information Systems and V-One

• BA, Psychology –Johns Hopkins University

In his spare time, Marcus likes playing strategy games, taking photos, making soap, woodworking, or forging swords.

Marcus Ranum, IANS Faculty member since 2018, delivers deep domain-level insights across cloud & application security, security research & threats, cloud & web application penetration testing, security automation, cyber risk management.