In this chapter, I want to acknowledge and highlight some of the cybersecurity thought leaders who have shaped defense strategies and the underlying technologies over the last quarter century. These are the luminaries who advanced cryptography, pioneered ethical hacking, and ushered in new ways to protect data on a global scale. Like modern-day rock stars—and many of them truly are—they’ve risen to every challenge the digital realm has thrown at them. So, to start, here are a few of those thought leaders who have made an indelible impression on my own journey.