Cybersecurity Architecture: Five Principles to Follow

1. Five Foundational Security Principles

The five core principles that are essential for building a robust cybersecurity architecture.

1. Defense in Depth: This principle is about creating multiple layers of security so that no single security mechanism is solely responsible for protecting a system. The analogy of a medieval castle with thick walls, a moat, and a drawbridge is used. In a modern IT example, this means using a combination of Multi-Factor Authentication (MFA), Endpoint Detection and Response (EDR), firewalls, and data encryption. If one layer fails, the others can still protect the system (FAILSAFE)

2. Least Privilege: Users and systems should only be given the minimum level of access and permissions required to perform their specific tasks. This prevents unauthorized access and minimizes the potential damage from a compromised account. This principle also involves hardening systems by removing unnecessary services (like FTP or SSH on a web server) and changing default credentials. It actively combats "privilege creep," where users accumulate unnecessary permissions over time.

3. Separation of Duties: This principle ensures that no single person has complete control over a critical process. It requires the involvement of at least two people to complete a task, making collusion necessary to compromise a system. For example, a person who requests access to a database cannot be the same person who approves that request. This prevents a single point of failure and makes it harder to conceal malicious activity.

4. Secure by Design: Security should not be an afterthought or something "bolted on" at the end of a project. Instead, it must be integrated into every phase of development, from initial requirements gathering to design, coding, testing, and production. The responsibility for security belongs to everyone—designers, administrators, and users—but it must start with the initial design.

5. Keep It Simple, Stupid (KISS): Security should be as simple as possible without sacrificing effectiveness. If security measures are too complex or cumbersome, users will find ways to bypass them, creating new vulnerabilities. The goal is to make it easier for "good guys" to do the right thing while making it difficult for "bad guys" to get in. For example, complex password rules can lead users to write down their passwords, defeating the purpose of the security rule.

---

2. The One Principle to Avoid: Security by Obscurity

This is the one security principle you should never rely on. Security by obscurity is the idea that a system is safe because its inner workings are unknown to an attacker. This is a false sense of security, as history has shown that relying on secrecy is a failed strategy.

A prime example is Kerckhoffs's Principle, which states that a cryptographic system should be secure even if everything about it is known except for the key. Truly secure systems like AES and RSA are "glass box" security; their algorithms are public and peer-reviewed, and their security relies solely on the secrecy of a private key, not on a secret method.