SSO and Identity Migration Playbook

Single sign-on (SSO) lets users authenticate once with a central identity provider (IdP) and access many applications. This playbook consolidates scattered, per-app logins onto one IdP using open standards — OpenID Connect (OIDC) and SAML for authentication, SCIM for automated user provisioning. The result is fewer passwords, stronger security, and centralized control over who can access what.

Identity migrations are sensitive: get them wrong and users are locked out of everything at once. The program therefore favors gradual, parallel-run cutover over a hard switch.

Phase-by-Phase

Discovery (3 weeks). Inventory every authentication system and user directory. Map which apps use which login method and where identities live today. This reveals the scope and the duplication to be consolidated.

Identity Provider Setup (4 weeks). Deploy the central IdP and synchronize it with authoritative directories. Secure its secrets and signing keys carefully, since the IdP becomes a high-value target.

Application Onboarding (5 weeks). Integrate applications via OIDC or SAML and automate user lifecycle with SCIM so accounts are created, updated, and deprovisioned automatically. Manage IdP configuration as code for repeatability.

MFA and Access Policies (4 weeks). Enforce multi-factor authentication, preferring phishing-resistant WebAuthn, and define conditional access policies aligned with least privilege and zero-trust principles.

Cutover and Decommission (3 weeks). Migrate users using an expand-and-contract approach — run new and old auth in parallel, move cohorts gradually, then retire legacy auth once verified. Keep incident response ready in case of issues.

Team and Roles

A security architect owns the identity strategy and standards choices. Security engineers configure the IdP, MFA, and access policies. DevOps manages IdP-as-code and integrations. Backend teams adapt applications to OIDC/SAML and SCIM. Clear communication to users is essential during cutover.

Risks and Mitigations

Lockout is the worst-case failure; mitigate with parallel running, break-glass accounts, and staged cohort migration. Incomplete provisioning leaves orphaned or missing accounts; SCIM automation and reconciliation reports address this. Broken integrations are caught by testing each app in a staging realm before production cutover.

Success Criteria

High SSO coverage across applications, broad MFA adoption, and a drop in authentication-related support tickets. A mature program deprovisions access automatically when someone leaves, closing a common security gap.

Tooling

Keycloak, Auth0, or Clerk serve as the IdP; Vault secures keys and secrets; NGINX or a gateway can enforce auth at the edge. Standards are OAuth 2.1, OpenID Connect, SAML 2.0, SCIM 2.0, and FIDO2/WebAuthn.