“Zero Trust” might not be the best life advice, but in the world of computer security this guideline has become essential. “Zero Trust is fundamentally a paradigm shift, going away from ‘perimeter defense’ to thinking it from the inside out,” says Gregory Garrett, vice president of cybersecurity for Peraton. And that’s because the biggest threat today is from cybercriminals who attack from within, using identity theft to compromise systems they couldn’t reach otherwise. This will require more adaptive identity verification systems that keep track of human behavior over time, says Thomas Afferton, president of Peraton’s Cyber Mission Sector. Here, Afferton and Garrett talk with John Gilroy, an instructor in the Master’s in Information Technology Management program at Georgetown University, about the nationwide effort to strengthen computer networks.