IAM, PAM, and identity governance teams share accountability because the risk spans sign-in, recovery, and privileged access. Security ownership should follow the access path, not the authentication label. If a system still accepts passwords, someone must own its residual exposure, even when passkeys are available elsewhere.
Why This Matters for Security Teams
hybrid authentication creates a split responsibility problem: passkeys may reduce phishing risk, but passwords, recovery flows, and fallback paths still carry exposure until they are fully retired. The accountable owner is not the authentication method itself, but the system that allows the residual path to exist. That means IAM, PAM, and identity governance teams all have a stake, with control boundaries tied to sign-in, reset, and privilege escalation.
This is exactly where identity programs drift into ambiguity. NIST Cybersecurity Framework 2.0 treats identity as a cross-cutting security concern, and NHIMG research shows how often residual identity exposure persists in practice: the Ultimate Guide to NHIs notes that 71% of NHIs are not rotated on time and 97% carry excessive privileges. The same governance pattern applies to human authentication when a “better” method exists but the older method remains active. In practice, many security teams encounter this only after a recovery path, legacy app, or admin exception has already become the easiest way in.
How It Works in Practice
Accountability should follow the access path. If passwords still authenticate users, the team that owns the application or identity provider must own the residual password risk, even if passkeys are enabled for primary login. If the highest-risk step is recovery, then the owner of enrollment, reset, or helpdesk verification owns that exposure. If privileged actions can still be reached through password-based escalation, PAM and identity governance must treat that path as in scope, not as an edge case.
Practically, this means mapping every authentication path and assigning control ownership at each stage:
- Primary sign-in: password, passkey, or both
- Recovery and re-enrollment: reset links, helpdesk approval, backup factors
- Privileged access: admin elevation, session approval, step-up checks
- Policy enforcement: MFA requirements, conditional access, and deprecation timelines
Teams should also measure whether the “secure” path is truly dominant. A passkey rollout does not eliminate risk if password reset remains weaker than sign-in, or if service desks can override controls with minimal verification. The NIST SP 800-53 Rev. 5 Security and Privacy Controls is useful here because it frames identity assurance, access enforcement, and system authorization as separate control responsibilities rather than a single checkbox. NHIMG’s Top 10 NHI Issues reinforces the broader lesson: hidden identity paths often survive because no one owns their end-to-end lifecycle. These controls tend to break down when legacy applications require password fallback, because exception handling quietly becomes the real production policy.
Common Variations and Edge Cases
Tighter authentication policy often increases operational overhead, requiring organisations to balance phishing resistance against support burden, application compatibility, and recovery safety. Best practice is evolving, and there is no universal standard for exactly when a password can be removed without creating unacceptable operational risk.
Common edge cases include shared admin consoles, third-party SaaS tools that still lack passkey support, and account recovery flows that depend on email or helpdesk verification. In those environments, the risk is not just the login method but the weakest surviving path. A password may be “disabled” for most users yet remain active for break-glass accounts, emergency support, or API-integrated workflows. That makes governance harder, not easier.
Security teams should treat hybrid authentication as a transition state with explicit owners, expiry milestones, and compensating controls. The practical test is simple: if a password can still unlock access, reset access, or restore privilege, the system remains accountable for password risk until that path is removed or materially hardened. In other words, passkeys reduce exposure only when the older path is actually retired, not merely de-emphasised.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Non-Human Identity Top 10 and CSA MAESTRO address the attack and risk surface, while NIST CSF 2.0, NIST SP 800-63 and NIST AI RMF set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST CSF 2.0 | PR.AC-1 | Identity governance must own who can access systems through any remaining password path. |
| NIST SP 800-63 | IAL/AAL/FAL | Hybrid auth risk depends on assurance across enrollment, authentication, and federation. |
| OWASP Non-Human Identity Top 10 | NHI-03 | Residual secrets and fallback credentials create the same exposure pattern as unmanaged NHI credentials. |
| CSA MAESTRO | Hybrid identity flows in agentic systems need explicit control ownership and path-based accountability. | |
| NIST AI RMF | GOVERN | Risk governance must define who owns residual authentication exposure and exception handling. |
Map ownership to each access path, including recovery and privilege escalation, then enforce it continuously.
