Secure Authentication and Authorization with Oauth 2.0 and OpenID Connect

The token request hits your endpoint. You must decide if it’s trusted. Oauth 2.0 and OpenID Connect (OIDC) give you the tools to make that decision without leaking data or risking compromise.

Oauth 2.0 is a protocol for delegated authorization. It defines flows for obtaining and using access tokens. These tokens grant scoped permissions from one system to another, without revealing the user’s credentials. Clients request authorization, receive tokens from an Authorization Server, and use them to call protected APIs.

OpenID Connect builds on Oauth 2.0. It adds an identity layer so you can verify who the user is, not just what they’re allowed to do. It uses ID tokens in JWT format, signed by the provider, to carry user identity claims. This means a client can authenticate and authorize in a single process, using a proven standard.

Common Oauth 2.0 flows include Authorization Code, Client Credentials, and Device Code. OIDC typically relies on the Authorization Code flow, extended with the openid scope, to retrieve both access and ID tokens. Security features like PKCE protect against interception attacks. Token validation requires checking signatures, issuer, audience, and expiration.

Integrating Oauth 2.0 with OpenID Connect ensures that every API request can be tied to a verified subject and clear permission boundaries. It reduces the risk of token replay, supports single sign-on, and enables fine-grained access controls across services. Providers like Google, Microsoft, and Okta follow these protocols, making interoperability straightforward when you adopt the standards.

Performance and security depend on correct implementation. Always use HTTPS. Store tokens securely. Rotate keys. Validate inputs. Explicitly handle refresh tokens to maintain long-lived sessions without re-prompting the user unnecessarily.

The combination of Oauth 2.0 and OIDC is now the baseline for secure, modern authentication and authorization. It is portable, well-documented, and battle-tested in production at scale.

See Oauth 2.0 and OpenID Connect running in minutes with real APIs. Try it now at hoop.dev.