Christopher Frenz is an enterprise CISO, a 2x Top 100 CISO, and the founder of the Subtractive Security movement. He serves as the project lead for the OWASP Subtractive Security Top 10, an open-source engineering initiative focused on using architectural controls to eliminate attack paths. A longtime pioneer in attack path management, Frenz developed pre-category-creation Breach and Attack Simulation (BAS) tooling to measure malware propagation and validate segmentation efficacy. Widely recognized for his foundational work in Zero Trust, microsegmentation, medical device security, and evidence-based methods for measuring control efficacy, he continues to push the industry toward measurable, engineering-first security.