Mac served as the Director of Information Security at MBNA America. His security responsibilities included CERT, operational security, security architecture, enabling technologies, business resumption planning, security awareness education, penetration testing, and access administration. Prior to MBNA, Mac was the Technical Program Director for the Network Infrastructure Laboratory at GTE (now Verizon). While there, he helped develop strategies in security and transport technologies and led a team to design the security architecture for GTE's Internet services. He has also organized and participated in various simulated attacks (Tiger Teams) to identify weaknesses in security systems. Mac was also the Chief Computer Engineer at NASA's Marshall Space Flight Center and Security Architect at Mead Data Central (Lexus/Nexus). In addition to his industry work, Mac has consulted to the CTIA, NSA, Secret Service, FBI, CIA, Scotland Yard, the Royal Canadian Mounted Police, and various state and local law enforcement organizations. Mac has participated in the President's Network Security Standards Oversight Group to identify significant security issues in the Public Switched Network. He has demonstrated security technologies for the U.S. Congress and has organized numerous workshops and conferences on various aspects of information security. Microsoft recognized Mac as a leader in the field of information security by asking him to participate in the Chief Security Officer’s Council. Mac has over 25 years of experience handling computer attacks involving thousands of computers and has organized and participated in simulated attacks to identify weaknesses in security systems. Over the course of his career, Mac has designed and developed a variety of widely used computer-based security systems. He has lectured widely and published numerous technical papers. Mac earned his Ph.D. and M.S. degrees in Computer Science from the University of Alabama in Huntsville and a B.S. in Computer Science from Hofstra University. Mac is a Certified Secure Software Lifecycle Professional (CSSLP-Retired) and a Certified Information System Security Professional (CISSP-Retried) and was one of the authors of the original certification exam. Mac had been an adjunct Professor at Drexel University where he taught Information Security and currently teaches at Goldey-Beacom College.