100 Days of System Design Questions challenges

Design a single sign-on (SSO) system to provide seamless authentication and access control across multiple applications and services within an organization. The system should allow users to authenticate once and access multiple resources without needing to log in again. Consider factors such as authentication protocols, identity providers, token-based authentication, and federation standards in your design. Discuss how you would implement a centralized authentication service to authenticate users and issue access tokens. Additionally, address how you would handle user identity management, session management, and single sign-off (SSO) across different applications and platforms. Provide insights into the technologies, security mechanisms, and integration strategies you would employ to implement this SSO system effectively.