JWT (JSON Web Token) and OAuth are two forms of authentication that are used to verify a user’s identity in different ways. Both have key advantages and limitations, and knowing the differences between them is important when making a decision about which authentication method to use for your application.
Short answer
TL;DR If you have very simple scenarios, like a single client application, or a single API then it might not pay off to go OAuth 2.0. On the other hand, if there are lots of different clients (browser-based, native mobile, server-side, etc) then sticking to OAuth 2.0 rules might make it more manageable than trying to roll your own system.
JWT
JWT authentication is an open standard for securely transferring information – usually JSON objects – between two parties, typically from one server to another.
This allows users to log in with one set of credentials on multiple applications and websites given that the data has been signed by a valid private key.
JWT authentication works by signing and verifying a token sent with each request, meaning they are cryptographically signed so they cannot be tampered with or created without both parties having shared access to the private key.
JWT is just a token format
OAuth
OAuth, on the other hand, is an authorization framework that focuses on giving third-party developers secure access to specific user data for a particular purpose. It does this by delegating user authorization from one party (usually called the resource server) to another (called the client).
OAuth works by providing tokens when the client attempts to access a resource on behalf of a specific user identified through their username and password, which it can obtain from its own service account or from an existing sign-on system like Facebook Connect or Twitter Login.
The token acts as proof of identity/authorization for accessing different resources limited in scope according to permissions within OAuth.
OAuth 2.0 defines a protocol, i.e. specifies how tokens are transferred
Difference between OAuth and JWT
OAuth 2.0 defines a protocol, i.e. specifies how tokens are transferred, JWT defines a token format.
There are several main differences between JWT and OAuth authentication:
- Goals: JWT is geared toward authentication while OAuth tends to be centered around authorization;
- Workflow: JWT simply requires comparing tokens while OAuth requires additional steps such as getting permission tokens and codes;
- Security: JWT encryption provides stronger security than most implementations of OAuth;
- Architecture: both have different architectures – JWT relies heavily on symmetric keys whereas OAuth relies heavily on public key cryptography;
- Protocol: JWT uses JSON payloads while OAuth implements OpenID Connect which utilizes JSON payloads itself along with other protocols like WS-Federation or SAML standards;
- Usability: since it’s simpler than OAuth, setting up client-side connectivity with JWTs is much easier than implementing the more involved redirects of grant types within Oauth.