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

When enterprise applications proliferate, isolated user data creates information silos; a unified, standardized account management system becomes essential for platform evolution, enabling single sign‑on, third‑party login, and ecosystem openness.

Terminology defines third‑party application (client), HTTP service (service provider), resource owner (user), user agent (browser), authorization server, and resource server.

Background describes the shift from monolithic session‑based authentication to token‑based approaches in RESTful and microservice architectures, highlighting token advantages: statelessness, performance, and cross‑device support.

Research Objectives aim to achieve flexible, standardized security authentication across heterogeneous systems via token mechanisms.

Typical Token Authentication Flow includes: (1) user submits credentials to the authentication service; (2) service validates and returns token data; (3) client includes the token in HTTP headers; (4) downstream microservices verify the token; (5) resources are returned.

Key Security Functions cover credential acquisition, login authorization, access verification, and token renewal.

Technical Selection adopts OAuth2 password grant as the authorization standard and JWT as the token format.

OAuth2 Overview explains the four grant types—authorization code, implicit, password, and client credentials—and their typical use cases.

JWT is introduced as a compact, secure JSON‑based token suitable for SSO and claim transmission.

Authentication Process Logic details system authorization, token issuance, resource access validation, and token renewal, illustrated with diagrams.

API Design describes endpoints for obtaining and renewing authorization credentials, including client code and secret handling.