SAML 2

SAML 2.0 is the industry-standard XML framework for exchanging authentication and authorization data between identity providers and service providers.

SAML 2.0 (Security Assertion Markup Language) eliminates password fatigue by enabling cross-domain Single Sign-On (SSO) through secure XML assertions. In a typical flow, an Identity Provider (IdP) like Okta or Microsoft Entra ID authenticates a user and passes a digitally signed token to a Service Provider (SP) such as Salesforce or Slack. This protocol relies on a trust relationship established via metadata exchange (including X.509 certificates) to ensure that sensitive user attributes move securely across the web. It remains the backbone of enterprise identity management, supporting complex use cases like identity federation and automated provisioning for thousands of SaaS applications.

https://www.oasis-open.org/standards#saml20