Quiz Entry - updated: 2026.10.22
What is a SAML protocol, and which protocols does SAML 2.0 define?
A SAML protocol is a request/response pattern, typically a request from the SP and the IdP's reaction to it; the main ones are Authentication Request, Single Logout, Assertion Query and Request, and Artifact Resolution.
| Protocol | Request, then response | Purpose |
|---|---|---|
| Authentication Request | <AuthnRequest>, then <Response> with assertion |
Obtain an authentication assertion to establish a security context at the SP; used by Web Browser SSO |
| Single Logout | <LogoutRequest>, then <LogoutResponse> |
End all sessions of a user at the IdP and every SP |
| Assertion Query and Request | <AssertionIDRequest>, <AttributeQuery>, <AuthnQuery>, then <Response> |
Fetch existing assertions by reference or search by parameters |
| Artifact Resolution | <ArtifactResolve>, then <ArtifactResponse> |
Exchange a short reference for the real message over a back channel |
| Name Identifier Management | <ManageNameIDRequest> |
Change or terminate a pseudonymous identifier |
| Name Identifier Mapping | <NameIDMappingRequest> |
Translate an identifier for use at another SP |
The protocols are transport-neutral: they define message content and processing rules, and a binding decides how each message actually travels.
Go deeper:
SAML 2.0: Protocols (Wikipedia) — each protocol with annotated XML examples.- OASIS: SAML V2.0 Core specification (PDF) — section 3 defines every protocol normatively.