Cybersecurity Architecture 101

Welcome, Students. Security is not a product you buy; it's a foundation you build.

The teaching materials are based on the Cybersecurity Architecture Series playlist by Prof. Jeff Crume.

Why Architecture Matters?

In cybersecurity, we assume that eventually, a tool will fail. Good architecture ensures that when one thing fails, the whole system doesn't collapse. We call this being Failsafe.

The 5 Pillars

Principle 1

Defense in Depth

Multiple layers of security. If a hacker passes the firewall, they still face MFA. If they pass MFA, they face encryption.

The Castle Analogy: A castle has a moat, a drawbridge, high walls, and internal guard dogs. One wall is never enough. In IT, this is combining MFA, firewalls, and encryption.

Principle 2

Least Privilege

Users should only have the minimum access required for their job. If they don't need to delete files, don't give them "Delete" rights.

Hardening: Turning off features the system doesn't need to reduce the "Attack Surface."
Privilege Creep: When an employee changes jobs but keeps old, unnecessary permissions.

Principle 3

Separation of Duties

No single person should have total control over a sensitive process. Ensure no single person has complete control over a sensitive process. This prevents internal fraud by requiring collusion (two people working together) to do something bad.

The Two-Key Safe: Like a bank vault that requires two different people to turn two different keys at the same time.

Principle 4

Secure by Design

Security is built into the project requirements from day one, not "bolted on" at the end. This is often called Continuous Integration of security.

The Earthquake Analogy: You build earthquake-proofing into the foundation of a skyscraper while building it. You don't try to add it after the building is 50 stories high.

Principle 5

KISS (Keep It Simple Stupid)

Simplicity is vital. If security is too complex for employees, they will find "wrong but easy" workarounds (like writing passwords on sticky notes).

The Danger: Security by Obscurity

This is the flawed idea that a system is safe just because its design is a secret. Attackers will eventually figure out the "Black Box."

Kerckhoff's Principle: A cryptographic system should be secure even if everything about it (except the key) is public knowledge.

Dictionary

SPOF Single Point of Failure. One part of a system that, if it breaks, brings down everything.

Re-certification Regularly reviewing user access to stop "Privilege Creep."

MFA Multi-Factor Authentication. Proving your identity with two or more "factors" (Password + SMS code).

AES/RSA Industry-standard encryption algorithms that are public and rigorously tested., not because they are "secret."

Collusion When two or more people work together to bypass "Separation of Duties."

Interactive Quiz

Click an answer to reveal the correct choice and explanation.