Design and Implementation of a Token‑Based Authentication System Using OAuth2 and JWT

When enterprise applications proliferate, isolated user data creates information silos; a unified account management system is essential for platformization, providing single sign‑on, third‑party login, and access control across services.

Key terminology such as third‑party application, HTTP service, resource owner, user agent, authorization server and resource server are defined to clarify the authentication model.

Traditional monolithic authentication relies on session‑based checks, whereas modern RESTful and microservice architectures favor token‑based authentication, offering statelessness, better performance, and cross‑device support.

The token‑based approach’s advantages include server‑side statelessness, reduced database lookups, and suitability for mobile and cross‑origin scenarios.

A typical token authentication workflow is outlined: user login, credential verification, token issuance, client attaching token to HTTP headers, resource server validation, and data return.

Security features such as credential acquisition, token validation, access control, and token renewal (refresh token) are described.

Technical choices adopt OAuth2 password‑grant flow and JWT as the token format, with diagrams illustrating system authorization, authentication logic, and interface design.