Single Sign-On (SSO) is a core authentication solution that simplifies user access while boosting security. With SSO, users can sign in once to access several applications, which cuts down on password-related threats, enhances user experience, and decreases IT support expenditures. SSO also improves compliance by mandating centralized authentication policy enforcement. Yet, SSO can be one point of failure if not properly secured. In order to counter likely attacks, companies can use Multi-Factor Authentication (MFA), embrace behavior-based analytics for anomalous behavior identification, and also enforce session time-outs and aggressive access restrictions. SSO becomes convenient and enterprise-grade security-friendly when appropriately hardened.