.NET Architecture & System Design Interview Question #151

What is authentication in system architecture?

Security Architecture, Multi-Tenancy & Disaster Recovery Senior Advanced

Quick Interview Answer

Authentication verifies the identity of a user, service, or application. It answers the question: who is making this request?

Detailed Explanation

Authentication verifies the identity of a user, service, or application. It answers the question: who is making this request?

In a distributed .NET system, authentication may use cookies, OpenID Connect, OAuth-based access tokens, certificates, or workload identities. Authentication should normally be centralized around trusted identity infrastructure rather than reimplemented independently by every service.

Code Example

User / Service
      |
Credentials or token
      |
Identity Provider
      |
Authenticated identity