Single Sign-On (SSO) has become a cornerstone of modern enterprise authentication, allowing users to access multiple applications with one set of credentials. This explainer breaks down the core concepts: how SSO works, the main protocols like SAML, OAuth 2.0, and OpenID Connect, and the architectural patterns that support it. We also examine critical security considerations, including token management, session handling, and the risks of centralized authentication. For developers and architects, understanding these fundamentals is essential for designing systems that balance user convenience with robust security. The article highlights common pitfalls, such as improper token validation and insecure session storage, and offers best practices for implementation. Whether you're building a small internal tool or a large-scale enterprise platform, mastering SSO principles ensures a seamless and secure user experience. This topic remains highly relevant as organizations increasingly adopt cloud services and need to manage identities across diverse environments.
This post covers the principles, protocols, architecture, and security design of Single Sign-On (SSO), a critical component for modern enterprise systems. It's an evergreen topic with high relevance for developers and architects designing authentication flows. The signal is the ongoing importance of secure and seamless authentication across multiple systems.