JSON Web Token vs OAuth2: What are the differences?

Introduction

In this Markdown code, we will provide a comparison between JSON Web Token (JWT) and OAuth2. The key differences between these two are outlined below.

1. Scalability: JSON Web Tokens (JWT) are self-contained, meaning that all the relevant information is included in the token itself. This makes them highly scalable as there is no need to query the server every time to verify the token. On the other hand, OAuth2 relies on tokens that are stored on the server-side and need to be queried each time a request is made, causing additional overhead and impacting scalability.

2. Token Generation: JWTs are generated by the server and include the necessary information to verify their authenticity, such as a digital signature. OAuth2, on the other hand, relies on access and refresh tokens generated by the authorization server. These tokens need to be requested and validated by a separate entity, which adds an extra step in the authentication process.

3. Scope of Authorization: OAuth2 provides a much finer-grained authorization mechanism by allowing the specification of different scopes for each access token. These scopes determine the level of access granted to a client application. In contrast, JWTs provide broader and more general authorization capabilities, as all the relevant information is already present in the token itself.

4. Token Expiration: JWTs have the option to include an expiration time, which allows for more granular control over their validity. This means that the server can specify the exact duration for which a JWT is considered valid and enforce stricter security measures. OAuth2, on the other hand, relies on short-lived access tokens and long-lived refresh tokens. The expiration time for these tokens is determined by the server and poses a potential security risk if not managed properly.

5. Token Revocation: In OAuth2, access and refresh tokens can be easily revoked by the authorization server, allowing fine-grained control over the access granted to client applications. JWTs, however, do not have a built-in revocation mechanism. Once a JWT is issued, it remains valid until it expires, which may pose a challenge when it comes to revoking access for a specific client.

6. Usage Pattern: JWTs are commonly used for authentication purposes, where the token itself contains information about the user and their permissions. OAuth2, on the other hand, is primarily used for authorization, allowing third-party applications to access resources on behalf of the user, without explicitly sharing credentials.

In summary, the key differences between JSON Web Token (JWT) and OAuth2 lie in their scalability, token generation process, scope of authorization, token expiration, token revocation mechanism, and usage pattern.