CISSP Made Simple

CISSP Made Simple – The 8 Security Domains Explained

The CISSP (Certified Information Systems Security Professional) certification is like a master’s toolkit for cybersecurity pros. It covers 8 big areas (called domains) that make up the (ISC)²

Common Body of Knowledge (CBK).Think of these domains as 8 pillars of security — together, they help you design, run, and protect any organization’s information systems from threats.

Here’s the beginner-friendly breakdown:

1. Security and Risk Management (16%)

This is the foundation of all security work. It’s about setting rules, understanding risks, and making sure everything you do follows the law and ethical standards.

What’s inside:

• Setting company-wide security policies.

• Following laws like GDPR, HIPAA, etc.

• Assessing risks and planning how to handle them.

• Business continuity planning (keeping things running during disasters).

• Following ethical guidelines for security pros.

  
  

Example: A company finds that its customer database could be hacked. They assess the risk, encrypt the data, and train employees to handle customer info securely.

2. Asset Security (10%)

This domain is all about protecting “what you own” — data, systems, and devices.

What’s inside:

• Classifying data (e.g., Public, Internal, Confidential).

• Setting rules for storing and deleting information.

• Protecting personal and sensitive information.

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Example: An organization encrypts confidential files and securely wipes hard drives before disposing of them.

3. Security Architecture and Engineering (13%)

Here we get into secure system design — building things to be safe from the start.

What’s inside:

• Designing secure software, hardware, and networks.

• Using security frameworks and models.

• Applying cryptography (encryption) to protect data.

• Making systems resilient to attacks.

  
  

Example: A company sets up multiple layers of security — firewalls, intrusion detection, and encrypted communication — to protect against hackers.

4. Communication and Network Security (13%)

This covers protecting data while it’s moving — emails, chats, file transfers, or any network traffic.

What’s inside:

• Designing secure networks (segmentation, VPNs, DMZs).

• Using secure protocols for communication.

• Securing wireless, mobile, and cloud systems.

  
  

Example: A retail business sets up a secure VPN for remote employees and encrypts all customer payment transactions.

5. Identity and Access Management (IAM) (13%)

IAM is about controlling who gets in and what they can do.

What’s inside:

• Managing user accounts.

• Using multi-factor authentication (MFA) and biometrics.

• Access control models (RBAC, MAC, DAC, ABAC).

• Single sign-on (SSO) systems.

  
  

Example: A company uses MFA and role-based access so employees only see the data they need for their job.

6. Security Assessment and Testing (12%)

You can’t improve what you don’t measure. This domain is about checking if your defenses actually work.

What’s inside:

• Vulnerability scans.

• Penetration testing.

• Security audits.

• Continuous monitoring.

  
  

Example: A security team runs monthly penetration tests to find weak spots before hackers do.

7. Security Operations (13%)

This is security in action — the day-to-day work of protecting systems.

What’s inside:

• Incident detection and response.

• Logging and monitoring activity.

• Disaster recovery planning.

• Forensics (investigating after a breach).

  
  

Example:

When a breach happens, the team uses logs to trace the attack, contains the damage, and updates defenses.

8. Software Development Security (10%)

This domain ensures that security is part of the coding process.

What’s inside:

• Writing secure code.

• Testing apps for vulnerabilities.

• Secure software development lifecycle (SDLC).

• Managing third-party software risks.

  
  

Example: Developers follow secure coding rules and use tools to detect vulnerabilities before releasing an app.

Key Notes for Quick Reading

• CISSP = 8 domains that together cover every aspect of cybersecurity.

• Risk Management is the foundation — know your risks before building defenses.

• Asset Security protects what you have.

• Architecture & Engineering builds safe systems from the start.

• Network Security protects data while it’s traveling.

• IAM ensures only the right people access the right data.

• Assessment & Testing finds weaknesses before attackers do.

• Security Operations keeps daily protection running.

• Software Security ensures apps are safe before launch.