OAuth and JWT have become important tools in modern technology and business environments. Both play an essential role in user experience and cybersecurity. OAuth is a well known adopted standard for authorization. Whereas, JWT is a token used for authentication and secure data exchange. Together, both OAuth and JWT not only improves operational efficiency but also form a reliable and strong layer of cybersecurity that protects against threats in modern digital sphere.

This blog explains what is OAuth and JWT and detailed comparisons between them.

What is OAuth?

OAuth (Open Authorization) is an open standard authorization framework that allows users to permit third-party applications limited access to their secured resources like emails, photos or social media posts without sharing their account passwords or login credentials. Instead of giving away sensitive or confidential information, these users authorize applications by granting them to obtain access tokens from an authorization server, which the third-party app can later use for accessing specific resources on behalf of user. In the last few years, over 8,571 companies globally implemented OAuth as an identity-and-access-management (IAM) tool, with the majority (59.57%) companies from the United States.  OAuth is most commonly used as the standard for authorization in APIs and web applications.

How OAuth Authentication Works

OAuth works through a series of interactions between four key roles:

1. Resource Owner: The user who owns the data and can grant access to it.

2. Client: The application requesting access to the user's data.

3. Authorization Server: The server that authenticates the user and provides access tokens to the client.

4. Resource Server: The server hosting the protected resources, that is capable of accepting and responding to protected resource requests by using access tokens.

The general flow:

1. Authorization Request: The client requests an authorization from resource owner.

2. Authorization Grant: Once the resource owner conducts authorization of the request, they provide authorization grant to client.

3. Access Token Request: The client submits the authorization grant to the authorization server and later requests an access token.

4. Access Token Response: The authorization server conducts authentication of the client and validates the authorization grant. Once its validation is done, it provides an access token.

5. Access for resource: The client uses the access token to access the protected resources hosted by the resource server.

Image source: manageengine

What is JWT (JSON Web Tokens) ?

A JSON Web Token (JWT) is an open standard (RFC 7519) that defines a compact, URL-Safe, self-contained way to transmit the information securely between parties as a JSON object. This information is digitally signed, which allows the recipient to verify authenticity and integrity of the data. JWTs can be signed using a secret (with HMAC) or a public/private key pair (using RSA or ECDSA) and can also be encrypted for confidentiality. JSON Web Tokens are commonly used in API authorization and authentication, especially for sharing JSON data between parties securely.

Structure of a JWT

A JWT comprises of three parts that are separated by periods (.) :

1. Header: Header mentions the token type (JWT) and the signing algorithm (e.g., HS267, RS267).

2. Payload: Payload contains the claims-statements about a the user or an entity and additional data. For instance: user ID, roles, or expiration time.

3. Signature: Signature is created by signing the encoded header and payload with a secret key or private key by using a specified algorithm. This maintains the token's authenticity and integrity.

Image source: fusionauth

How JWT Authentication Works

1. Login: The user logs in using the credentials.

2. Generation of Token: Once the credentials are submitted and becomes valid, the server generates a JWT that contains user information in the payload and signs it with a private key or a secret key.

3. Transmission of Token: The JWT is then sent to the client browser or app and will be stored in a local storage or as an HTTP-only cookie.

4. Subsequent Requests: The client includes the JWT in the Authorization header (as a Bearer token) with each request to secured endpoints.

5. Token Validation:

• The server decodes the JWT.

• It verifies the signature using a public key or secret key.

• It verifies claims like expiration time and issuer.

• If it is valid, the server processes the request, otherwise, it rejects it.

1. Statelessness: The server does not need to store session data-everything needed for authentication is inside the token which makes JWT suitable for scalable, distributed systems.

Image source: miniorange

Difference between OAuth and JWT

Here are some differences between OAuth and JWT:

Advantages of OAuth

1. OAuth's scope mechanism lets applications to request specific permissions to make sure third-party apps get access only for the data they require. This approach improves security and user privacy.

2. OAuth facilitates smooth implementations of SSO across multiple applications and domains. This allows users to authenticate just once and access multiple services without entering credentials repeatedly.

3. OAuth integrates built-in security controls such as token expiration and revocation and supports prompt mitigation of potential security breaches by invalidating compromised tokens.

4. As an industry-standard protocol, OAuth makes sure interoperability across various platforms and services which simplifies integration with various third-party services.

Disadvantages of OAuth

1. OAuth setup can be difficult, particularly for smaller projects or teams with limited resources.

2. OAuth’s architecture has various components (authorization server, resource server, client) which can increase complexity of system and potential points of failure.

3. The extra steps in the OAuth flow like token exchange and validation could result in latency in API calls than compared to simple authentication steps.

4. Management of access and refresh tokens can be complex task particularly with multiple clients and resource servers. Issuing, storing, validating, and revoking tokens requires careful planning.

5. If an application demands too much access, this could lead users to unintentionally disclose confidential information.

Advantages of JWT

1. JWTs are self-contained and does not require server-side storage, and this makes them straightforward to implement and use in various scenarios.

2. All important information is encoded in the token itself which reduces the need for database lookups. This improves performance in distributed systems.

3. JWTs integrates well into modern stateless architectures, particularly in microservices environments where maintaining session state can be difficult.

4. JWTs work well across different domains which makes them ideal for mobile apps and single-page applications that interact with backend APIs.

5. JWTs can be signed and encrypted optionally which ensures data integrity and confidentiality. This makes them a secure way to transmit information between parties.

Disadvantages of JWT

1. Once JWTs are issued, it cannot be revoked easily before the expiration time. This can be a security concern if a token is compromised.

2. Improper handling of JWTs can result in vulnerabilities. Storing sensitive information in the payload (which is base64 encoded, not encrypted) can expose and has probability of getting exploited if the token is intercepted.

3. All the information is contained in the token, it can become large particularly with many claims. This could affect performance when tokens are sent with every request.

4. JWTs does not provide measures to control access at a granular level without custom implementation.

How can OAuth2 and JWT Work Together ?

OAuth2 and JWT serve different purposes but still they are often used together. OAuth2 does not define a specific token format. It allows JWT to be used as the access token. By integrating additional data in a JWT, applications can minimize communication between resource and authentication servers which helps in improved performance.

Sometimes, systems issue two tokens; a reference token and a JWT containing user identity details. But, if identity handling is key, OpenID Connect (an OAuth2 extension) might be ideal. It's a myth that using JWT automatically improves security. OAuth2 security depends more on accurate flow selection than token type. JWT can improve performance and streamline some of the workflows but may also introduce development complexity.

Consider the outcomes of performance against the additional workflow before adopting JWT with OAuth2.

Factors to Consider when Choosing the Right Solution

To choose the right solution between OAuth and JWT, consider the below factors that align with the business and security requirements.

Type of Application

For applications that require delegated access (e.g., allowing a third-party app to access user data), OAuth2 is more ideal. For internal authentication within your own application, JWT is suitable.

Session Management

If your application gets advantage from stateless authentication (e.g., in microservices architectures), JWTs can minimize server load. But, if you need a feature to manage sessions centrally or revoke tokens, OAuth2 is more suitable.

Security Measures

OAuth2 offers mechanisms for token revocation and scopes and provides fine-grained access control. JWTs are self-contained and require proper management to prevent exploitation if a token is compromised.

Maintenance and Complexity

Implementing OAuth2 can be more challenging due to multiple components and flows. JWTs are easier to implement but require strong and reliable security measures to ensure token integrity and confidentiality.

Final Thoughts

By considering above factors you can choose the right authentication mention that ideally fits your security requirements.

Akto API Security platform offers complete support for OAuth 2.0 and JWT. It automatically detects standard authentication methods like JWT and Bearer tokens. Besides this, it supports custom authentication schemes to ensure reliable and strong security protection against unauthorized access. With over 100 built-in test cases, Akto vigorously tests your APIs for authentication and authorization vulnerabilities such as JWT weaknesses and session management issues.

Integrate Akto seamlessly into your CI/CD pipelines to automate API security testing and maintain a strong security posture. Book a demo right away to see Akto in action!