Explore a DEF CON 31 conference presentation that examines vulnerabilities in contactless credential systems, focusing on a specific weakness in the ISO 14443A protocol enabling relay attacks over long distances. Learn about the evolution of contactless credential attacks, manufacturer adaptations, and the technical aspects of executing relay attacks. Discover how a new Proxmark tool demonstrates unlocking a door in Ottawa remotely from Las Vegas, while gaining insights into HID Global's response to responsible disclosure and practical mitigation strategies for protecting access control systems.