An identity provider (IdP) is the central service that manages identities and performs logins: users authenticate with the IdP, which issues signed proofs (SAML assertions, OIDC tokens) to connected applications. Well-known representatives are Microsoft Entra ID, Okta or Google Workspace.
The IdP is thus the pivot of modern access architectures: SSO, MFA, passkeys and conditional access converge here — and Zero Trust platforms obtain the identity for every access decision from it.
What role does the IdP play in the architecture?
Applications delegate their login to the IdP and trust its signed tickets — they no longer store passwords themselves. ZTNA and SASE platforms couple directly: every access decision queries identity and group membership at the IdP, complemented by context such as device posture.
This centrality makes the IdP the most protection-worthy service in the environment: strong authentication for everyone (especially administrators), hardened configuration, monitored logs and rehearsed recovery processes are mandatory.
What matters in IdP operations
- Phishing-resistant login — mandatory at least for admin accounts.
- Clean directory hygiene: lifecycle, groups, no orphaned accounts.
- Conditional access rules for context: device, location, risk.
- Feed logs into detection: login anomalies are early warning signals.