Security Assertion Markup Language (SAML)

SAML is a federation standard commonly used to carry authentication and identity assertions between an identity provider and an application.

SAML, short for Security Assertion Markup Language, is a federation standard used to exchange identity information between systems. In plain language, it often lets an identity provider tell an application that a user has already authenticated and provide selected identity details the application needs to trust that result.

Why It Matters

SAML matters because it is one of the main building blocks behind enterprise Single Sign-On. Instead of every application storing and verifying its own separate credentials, organizations can centralize login through an identity provider.

It also matters because federation changes where security policy is enforced. When SAML is part of the login flow, organizations can apply stronger authentication, revocation, and auditing at the identity-provider layer rather than reinventing them in every application.

Where It Appears in Real Systems or Security Workflow

SAML appears in workforce SaaS login, higher-education portals, partner access, and many enterprise web applications. A user authenticates with the identity provider, and the application accepts a SAML assertion confirming the identity and related attributes.

Security teams evaluate SAML during SSO rollout, federation troubleshooting, and identity hardening projects. They care about which applications trust which identity provider, what attributes are released, and how strong the upstream authentication is.

SAML Compared With OIDC

QuestionSAMLOIDC
Common fitTraditional enterprise federationNewer web and mobile sign-in
Main exchange styleIdentity assertions between enterprise systemsToken-based identity layer on OAuth
Typical deploymentWorkforce SaaS and browser-based appsModern app platforms and APIs

Practical Example

An employee opens an HR application from the company portal. The employee is redirected to the identity provider, completes authentication there, and returns with a SAML assertion. The HR application trusts that assertion and creates the user session without storing a separate password for that employee.

Common Misunderstandings and Close Contrasts

SAML is not the same as SSO as a whole. SSO is the broader user experience or architecture pattern. SAML is one specific federation standard often used to support that pattern.

It is also not the same as authorization itself. SAML can carry identity attributes that influence access decisions, but the application still needs its own Authorization logic.

Knowledge Check

  1. What does SAML usually help an application trust? That a user has already authenticated with a trusted identity provider.
  2. Is SAML itself the same thing as SSO? No. SSO is the broader pattern, and SAML is one standard often used to support it.
  3. Does SAML remove the need for authorization in the application? No. The application still needs to decide what the user is allowed to do.
Revised on Friday, April 24, 2026