The term “Defense in Depth” has been around for a long time and is sometimes difficult to define.
The best definition I’ve heard is as follows from Chris Cochran: “Defense in depth is about more than protecting your perimeter; it’s about adding defenses as you get closer to your critical assets.”
In practice, the most reliable layer is people. Invest in clear playbooks, incident rehearsals, and empowering teams to act quickly when signals appear.
- Run tabletop exercises quarterly.
- Map detections to owners.
- Automate first responses where safe.