OAuth vs. OIDC: What's the Difference and When Should You Use Each?
Security Boulevard, Monday, October 27th, 2025
Engineers conflate Open Authorization (OAuth) and OpenID Connect (OIDC) constantly, building authentication systems when they need authorization frameworks, or parsing access tokens for identity information they should extract from ID tokens.
This often results in security gaps, unnecessary complexity, and architectures that violate the fundamental separation between proving identity and granting access.
OAuth handles authorization, while OIDC handles authentication. Mix them up and you'll either over-engineer identity verification where simple access control suffices, or leave critical identity gaps in systems that need cryptographic proof of who's requesting access.