Introduction to AuthN and AuthZ

Back to AuthN & AuthZ
Arjit Sharma
01 Min

In modern application development, two concepts often appear side by side: Authentication (AuthN) and Authorization (AuthZ). While they are closely related, they serve different purposes in securing systems and applications.

🔑 Authentication (AuthN)

Authentication is the process of verifying who a user or system is. It answers the question: “Are you really who you claim to be?”

Common authentication methods include:

  • Username and password
  • Multi-factor authentication (MFA)
  • Biometrics (fingerprint or facial recognition)
  • OAuth/OpenID Connect tokens

Think of authentication as the digital equivalent of showing your ID card at the entrance of a building.

🛡️ Authorization (AuthZ)

Authorization determines what an authenticated user is allowed to do. It answers the question: “Now that we know who you are, what can you access?”

Examples:

  • A regular user can view their own profile but cannot edit others’ profiles.
  • An admin can manage system settings, while a guest cannot.
  • Role-Based Access Control (RBAC) and Attribute-Based Access Control (ABAC) are common authorization models.

Authorization is like a security guard checking whether your ID card grants you access to specific rooms inside the building.

🚀 Conclusion

Understanding the difference between AuthN and AuthZ is crucial for developers building secure systems.

Without authentication, anyone could impersonate a user. Without authorization, authenticated users could access everything without restriction. Together, AuthN and AuthZ form the foundation of secure application design.

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