Defense in Depth
ELI5 — The Vibe Check
Defense in Depth means layering multiple security measures so if one fails, others catch the threat. Firewall AND authentication AND encryption AND monitoring AND rate limiting. It's like wearing a seatbelt AND having airbags AND having crumple zones. No single point of failure.
Real Talk
Defense in depth is a security strategy employing multiple redundant layers of protection (network, application, data, physical). Each layer operates independently, ensuring that compromise of one layer doesn't lead to full system compromise. Aligns with Zero Trust and principle of least privilege.
When You'll Hear This
"Defense in depth means we don't rely on just the firewall — every layer has its own security." / "Even if the WAF misses an attack, input validation and parameterized queries catch it."
Related Terms
Network Segmentation
Network Segmentation divides your network into isolated zones. The web servers can't talk to the database directly.
Principle of Least Privilege
Principle of Least Privilege means everyone and everything gets only the MINIMUM access needed to do their job. The intern doesn't get admin access.
Security Headers
Security Headers are HTTP response headers that tell browsers 'here's how to protect my users.
Zero Trust
Zero Trust means 'never trust, always verify.' Even if you're inside the company network, you still have to prove who you are for every request.