The Security Assertion Markup Language (SAML), was developed by the OASIS Security Services Technical Committee (SSTC). It provides an XML-based framework--both structures and processes--for authorities to exchange authentication, attribute and authorization information about a subject. The subject is usually a person, but may be a computer or other entity, as long as it exists in some security domain. SAML provides a standard way to do single sign-on (SSO) that works independently of the underlying business systems and therefore can be an integral part of Federated Identity Management (FIM).

The previous browser-based methods for maintaining identity during a session had serious deficiencies which the designers wanted to address, including the issues associated with using cookies to establish authenticated sessions. Cookies do not let one organization vouch for an entity that they’ve already authenticated, but SAML assertions support this.