John Byun is the Chief Information Security Officer for Sephora North America, where he leads all cybersecurity operations and strategy. Known for challenging conventional security orthodoxy, he champions a forward-looking approach built for a rapidly evolving threat landscape, embracing AI-driven innovation over legacy best practices. His leadership reflects a conviction that security must evolve as fast as the technology and risks it defends against.
One of our proudest achievements has been transforming our cybersecurity program from a relatively immature state into the most mature and forward-thinking across LVMH, outpacing over 40 other CISOs in just a few years. We have consistently led the group in adopting and implementing cutting-edge technologies, including passwordless authentication via biometrics and device trust, ransomware resilience, Network Detection & Response, CWPP, CSPM, API security, CAASM, PAM, automated penetration testing, SaaS security, and next-generation bot protection. As a result, other brands across LVMH regularly turn to us for strategic guidance on developing and strengthening their own cybersecurity programs.








