Authentication vs Authorization

Authentication

Authentication verifies who you are. It answers: "Are you really who you claim to be?"

Common Authentication Methods

• Username/Password: Traditional but vulnerable to weak passwords
• OAuth 2.0: Delegate authentication to third parties
• JWT Tokens: Stateless, scalable authentication
• Multi-Factor Authentication (MFA): Additional security layer
• Biometric: Fingerprint, facial recognition

Authorization

Authorization determines what you can do. It answers: "What are you allowed to access?"

Authorization Models

Role-Based Access Control (RBAC)

Assign users to roles with specific permissions.

User → Role (Admin, Editor, Viewer) → Permissions

Attribute-Based Access Control (ABAC)

Fine-grained control based on attributes, resources, and environment.

Can User (attributes) perform Action on Resource (attributes)?

Implementation Best Practices

For Authentication

• Hash passwords with bcrypt or similar
• Implement rate limiting on login attempts
• Use HTTPS for all authentication traffic
• Store tokens securely (httpOnly cookies)
• Implement session timeouts

For Authorization

• Apply principle of least privilege
• Check permissions on every request
• Log authorization failures
• Use middleware for consistent checks
• Separate authentication from authorization

Security Considerations

• Never trust the client for authorization decisions
• Always verify permissions server-side
• Use secure token storage mechanisms
• Implement proper logout (session invalidation)
• Monitor suspicious authentication patterns