What is OpenID Connect?

OpenID Connect (OIDC) is a pivotal protocol for businesses that want to offer secure and user-friendly login experiences. Built on top of OAuth 2.0, OpenID Connect enables seamless user authentication, powering solutions like “Sign in with Google” or “Login with Facebook.”

Rather than reinventing the wheel, OpenID Connect acts as a lightweight extension to OAuth, filling in the gaps needed to verify user identities efficiently and securely.

Why OpenID Connect Exists

OAuth 2.0 is exceptional for granting limited access to resources (e.g., letting an app read your contacts), but it wasn't designed for authentication—verifying who a user is. However, many businesses started using OAuth for user login anyway, leading to inconsistent implementations across providers like Google and Facebook.

OpenID Connect was developed to standardize this process, making user login consistent, secure, and easier to implement. For businesses, this means less complexity and more confidence in authentication workflows.

How OpenID Connect Works

OpenID Connect builds on the OAuth 2.0 framework but introduces the ID Token, a secure token containing key details about the authenticated user. The process starts when a user clicks a button like “Sign in with Google” on an application. They are redirected to the authorization server, such as Google or Microsoft, where they securely log in and grant permission to share their data.

After successful authentication, the authorization server sends back an ID token to the application. This token, which is cryptographically signed, allows the application to decode the user’s identity. The process is fast, secure, and designed to work across multiple platforms, ensuring a seamless experience for users and developers alike.

Key Components of OpenID Connect

OpenID Connect introduces several components that revolutionize how authentication works. At the heart of the protocol is the ID Token, a JSON Web Token (JWT) containing essential user details like name, email, and a unique identifier. The ID token’s cryptographic signature guarantees its authenticity, ensuring it hasn’t been tampered with.

For applications requiring additional user data, the UserInfo Endpoint allows the application to request extra details using the access token. Scopes play a crucial role in tailoring the login experience. The openid scope signals an authentication request, while optional scopes like profile or email allow businesses to customize what user information is retrieved during the login process.

Why OpenID Connect Matters for Businesses

Authentication is more than just a way to let users into your app—it’s a foundation for building trust, ensuring security, and delivering a great user experience. OpenID Connect simplifies authentication by eliminating the need for custom-built login systems, saving development time and reducing complexity.

The protocol is highly interoperable, working seamlessly with major identity providers like Google and Microsoft, as well as custom enterprise systems. It enhances security by using cryptographically signed ID tokens, protecting against tampering and ensuring the integrity of user data. For users, OpenID Connect makes logging in easier and more familiar, reducing friction and encouraging higher adoption rates. For businesses, it’s a powerful tool to deliver secure and user-friendly authentication at scale.

How It's Different from OAuth

To understand OpenID Connect's value, it's essential to distinguish it from OAuth.

OAuth 2.0 is about authorization—granting applications permission to access resources on behalf of the user. For example, OAuth lets an app read your Google Calendar or retrieve your contacts. It's more focused on “what the app can do.”

OpenID Connect, on the other hand, is about authentication—verifying who the user is. It introduces the ID token, which contains user identity details like their name or email address.

Think of it this way: OAuth says, “This app is allowed to do X,” while OpenID Connect adds, “And here's who the user is while doing it.”

For businesses, using OpenID Connect ensures you're leveraging the right tool for user authentication without compromising security or scalability.

Common Use Cases

OpenID Connect powers many of the login flows businesses and users rely on every day. Here are some examples:

• Social Login: Allow users to log in with existing accounts from Google, Facebook, or other providers, reducing the need for new credentials.
• Enterprise Single Sign-On (SSO): Streamline employee access to multiple business tools and applications with a single set of credentials.
• Mobile App Authentication: Provide a seamless and secure login experience for native apps on iOS or Android.

These use cases highlight OpenID Connect's versatility in addressing both consumer-facing and enterprise-level authentication needs.

About UniSignIn

UniSignIn is a part of Transfon's privacy-first User Experience Platform serves tens of millions of users per day to provide a seamless privacy experience for both users and publishers in the age of post GDPR. Contact us to know more: [email protected]