Look for uneven adoption across user groups, repeated fallback to passwords or OTPs, and different recovery journeys for the same access tier. If high-risk transactions still rely on weaker methods in practice, the programme has introduced fragmentation rather than uniform phishing resistance.
What inconsistent assurance looks like after a passkey rollout
In practice, inconsistent assurance shows up when the rollout creates different authentication strength for different people or different journeys. A user may be “on passkeys” for everyday login but still be routed through passwords, OTPs, or a weaker recovery path when the account is reset, the device changes, or the transaction is higher risk. The result is a mixed trust posture, not a single phishing-resistant standard.
That inconsistency matters because passkeys are only as strong as the weakest path an attacker can still use to get into the account. If one population or one workflow still depends on legacy fallback, the programme is not yet delivering uniform assurance, even if the headline adoption number looks good.
Where the assurance gaps usually appear
One common sign is uneven adoption across user groups. Some teams, geographies, or device populations may be fully enrolled while others remain stuck on legacy factors because of platform limits, policy exceptions, or uneven support. That leaves assurance dependent on who the user is and where they sit in the organisation, which is exactly the kind of fragmentation a passkey programme should reduce.
Another sign is repeated fallback to passwords or OTPs. A healthy rollout should reduce dependence on those methods rather than merely add passkeys as an extra option. If users still choose weaker methods by default, or if support processes keep steering them back to easier recovery, the programme is preserving old risk instead of replacing it.
A third sign is inconsistent recovery for the same access tier. If one user can recover with a passkey-centric flow while another user in the same tier can reset through knowledge-based or OTP-based paths, the effective assurance level is no longer uniform. That is especially important for privileged or high-impact accounts, where recovery is often the real control boundary.
Why fragmented recovery undermines a passkey programme
Passkey assurance is not just about primary sign-in. It also depends on enrollment, device replacement, account recovery, and help desk handling. If those supporting processes are inconsistent, attackers will look for the weakest route rather than the strongest login method. That is why good passkey programmes treat recovery and fallback as part of the authentication design, not as an administrative exception.
For practitioners, the critical question is whether high-risk actions still accept weaker methods in practice. If sensitive transactions, admin changes, or account recovery can still be completed through passwords or OTPs, then the rollout has created a split between intended assurance and actual assurance. That gap is often larger than the visible authentication policy suggests.
Passkey deployment guidance should therefore be read alongside authentication assurance requirements such as NIST SP 800-63 Digital Identity Guidelines. The practical issue is not whether passkeys exist somewhere in the stack, but whether the whole sign-in and recovery journey consistently supports the intended assurance level.
Risk and Threat Considerations
Fragmented assurance creates a predictable attack surface: adversaries do not need to defeat the strongest path if they can route around it through a weaker fallback, a laxer recovery flow, or a user segment that has not fully converted. That is why inconsistent passkey adoption often increases, rather than decreases, the value of social engineering, help desk abuse, and credential fallback abuse.
Failure mechanism: The programme leaves alternate authentication and recovery paths in place, so the effective control becomes the weakest approved method rather than passkeys themselves. Attackers exploit that inconsistency by targeting users, support staff, or higher-risk workflows that still accept legacy verification.
Impact: The organisation gets the appearance of phishing resistance without uniform enforcement, which can preserve account-takeover risk in exactly the populations or transactions that matter most. Over time, that also makes policy exceptions harder to see and harder to retire.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
NIST SP 800-53 Rev 5, NIST SP 800-63 and NIST CSF 2.0 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST SP 800-53 Rev 5 | IA-5 — Authenticator Management | Passkey rollout depends on lifecycle control of authenticators and fallback methods. |
| IA-2 — Identification and Authentication (Organizational Users) | User sign-in assurance is directly about authenticating organizational users consistently. | |
| IA-8 — Identification and Authentication (Non-Organizational Users) | Where external users or mixed populations exist, assurance consistency must hold across those identities too. | |
| Recommendation — Control authenticator issuance, replacement, and revocation so weaker fallback paths do not persist. Enforce consistent authentication strength across user groups and access journeys. Apply the same assurance requirements to external identities and avoid weaker exception paths. | ||
| NIST SP 800-63 | Digital Identity Guidelines | The question turns on authenticator assurance, phishing resistance, and recovery consistency. |
| Recommendation — Map each sign-in and recovery path to the intended assurance level and remove weaker alternatives. | ||
| NIST CSF 2.0 | PR.AA-05 — Authenticator Management | Passkey rollout quality depends on managing authenticators and reducing fallback exposure. |
| Recommendation — Manage authenticators so fallback methods do not become the effective control. | ||
Practitioner Guidance
What to verify: Check whether passkey enrollment, login, step-up, and recovery all resolve to the same assurance target for each access tier. The moment one path is weaker than the others, treat the rollout as incomplete from a control perspective rather than merely “mostly deployed”.
Decision rule: If a user can still reach the same account or privilege level through passwords, OTPs, or help desk resets, do not describe the rollout as passkey assurance, describe it as mixed assurance with a phishing-resistant option. That distinction matters because it changes what must be remediated first.
What good looks like: Strong rollouts show low fallback rates, consistent recovery rules, and no high-risk workflow that depends on legacy factors once passkeys are available. For rollout design and recovery hardening, Passwordless and Passkeys Guide and Workforce Identity Security Guide are useful references for aligning sign-in, recovery, and support processes.
Practitioner takeaway: Do not measure a passkey programme by enrollment alone; measure whether the weakest surviving path is still strong enough for the account’s real risk.
Related resources from NHI Mgmt Group
- What are the signs that a passkey rollout is being misapplied in the enterprise?
- What are the signs that a passkey rollout is failing because the user journey is too rigid?
- What are the signs that a passkey rollout is working?
- What are the signs that a passkey rollout is misconfigured in a single page application?
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Reviewed and updated by the NHIMG editorial team on October 8, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org