# What is Federated Identity?

> Federated identity is an arrangement in which one administrative domain relies on identity and authentication information supplied by another trusted domain.

- Canonical URL: https://yellowcube.eu/glossary/federated-identity/
- Publisher: Yellow Cube
- Language: en
- Contact: hello@yellowcube.eu

## Content

An identity provider authenticates a person or other subject and issues a protected assertion to a relying party. The relying party validates that assertion and uses its contents to establish a local session or support another transaction.

Federation protocols such as OpenID Connect and Security Assertion Markup Language define how assertions and related metadata move between parties. The trust agreement and implementation must define accepted issuers, keys, audiences, subject identifiers, attributes, assurance, lifetimes, and privacy rules. Local account mapping, provisioning, and authorization remain responsibilities of the relying service or connected lifecycle systems.

### Key points

- **Trust establishment:** Parties agree how issuers and relying parties are identified, how keys and metadata are maintained, and which protocol profiles are accepted.
- **Assertion validation:** Check issuer, signature, audience, time bounds, transaction binding, subject mapping, and other protections required by the chosen protocol.
- **Lifecycle and privacy:** Limit released attributes, handle identifier changes, revoke or disable access promptly, and understand what activity the identity provider can observe.
- **Important limitation:** Federation shifts and concentrates trust; it does not eliminate compromise. Stolen signing keys, unsafe account linking, replayable assertions, weak authentication, or a compromised identity provider can affect every relying party that accepts the result.

### Related terms

[Single sign-on (SSO)](<https://yellowcube.eu/glossary/single-sign-on/>) · [OpenID Connect (OIDC)](<https://yellowcube.eu/glossary/openid-connect/>) · [Security Assertion Markup Language (SAML)](<https://yellowcube.eu/glossary/security-assertion-markup-language/>) · [Identity as a service (IDaaS)](<https://yellowcube.eu/glossary/identity-as-a-service/>) · [Multi-factor authentication (MFA)](<https://yellowcube.eu/glossary/multi-factor-authentication/>) · [Identity provider (IdP)](<https://yellowcube.eu/glossary/identity-provider/>)

### Sources

[NIST SP 800-63C-4: Federation and Assertions](https://csrc.nist.gov/pubs/sp/800/63/c/4/final) · [NIST SP 800-63C-4: Common Federation Requirements](https://pages.nist.gov/800-63-4/sp800-63c/Federation/)

## Attribution and scope

This Markdown representation is generated from the same approved content records as the canonical HTML page. Cite the canonical URL above when referencing this material. Product and service descriptions are informational; confirm project-specific requirements with Yellow Cube.