Follow (and One to Avoid)
Cybersecurity Architecture Fundamentals:
A defence-in-Depth Approach
Cybersecurity Architecture: Understanding the
Basics
Cybersecurity is more important than ever in today’s digital world. Think
of it like protecting a valuable treasure—you wouldn’t use just one lock
or one wall. Instead, you’d use several layers of protection to keep it safe.
That’s exactly what this series is about: the key ideas (called principles)
behind strong cybersecurity.
We’ll look at five important security principles—the building blocks of
good cybersecurity—and also talk about one thing you should never do.
Principle 1: defence in Depth
Let’s start with the first principle: defence in Depth.
The idea is simple—don’t rely on just one layer of security. Instead, use
many layers to make it harder for attackers to get in. Think of it like an
obstacle course: the more hurdles an attacker faces, the better your
chances of stopping them.
A great example comes from history. Imagine a castle. Castles had thick
walls to keep enemies out. But people needed to go in and out, so they
added a door. That door became a weak point. One wall wasn't enough
—so they added more walls, moats, guards, and watchtowers.
That’s what defence in Depth means in cybersecurity—if one defence
fails, others are still there to protect you.
, System Hardening and the Principle of
Least Privilege
Security Principle #1: defence in Depth
defence in Depth means not trusting just one security tool or measure to
protect your system. Instead, you use many layers of defence—like
building a strong, smart fortress.
🏰 Think of a Castle…
Imagine protecting a castle. Would you only use a strong door? No!
You’d:
Add a moat around the castle
Use a drawbridge to control who enters
Maybe even have an angry dog guarding it
Each of these adds another layer of protection. The goal? To slow down
or stop attackers at every step.
🔒 A Modern Example: Protecting a Database
Now imagine a person trying to access a secure database. They go
through several steps:
1. Their own computer or phone (workstation)
2. Through the network
3. To a web server
4. Then to an application server
5. And finally, reach the database
If just one of these steps is weak, an attacker could break in. That’s
where defence in Depth helps—by protecting each layer.