External Identity Provider

Overview
An External Identity Provider (IPS) is

"[a] service or system that establishes an individual's identity and links the identity to a physical or electronic credential or token. IDP's validate the identity of the individual using the credential or token issued and pass along verification of the individual's identity to a relying party, usually through a SAML assertion. Within this Use Case, External IDPs are agency systems, other than the agency performing the validation. External IDP's are those systems or services that are not directly controlled or managed by the agency."