Security keys should be treated as a second factor, not a replacement for strong credentials. The practical model is to keep unique passwords or a password manager in place, then add a hardware key for sign in from new devices and other high risk logins. That combination reduces remote takeover risk, but it still depends on strong password hygiene and recovery planning.
Why security keys work best as an added factor, not a password substitute
Security keys improve account protection because they add a phishing-resistant sign in step, but they do not remove the need for a strong password or equally strong primary credential. The key protects the interactive login path, while the password still anchors account recovery, fallback access, and coverage for systems that do not yet support key-only sign in. Treat the key as a hardening layer, not the whole control.
A good mental model is “strong password first, then key for step-up and high-risk access.” That matters because a stolen password still becomes useful anywhere the key is not enforced, including legacy flows, support workflows, or recovery channels. Teams get the most value when the password remains unique and resistant to guessing, reuse, and stuffing, while the key blocks remote phishing and token relay.
For a broader view of how keys fit into modern sign-in design, the Passwordless and Passkeys Guide is useful because it explains the relationship between phishing-resistant authenticators, passkeys, and secure recovery. Password hygiene still matters, and the Password Security and Password Manager Guide supports the password side of that model.
Where teams should require the key, and where the password still matters
Security keys are most valuable at the moments that attract attackers: new device sign-ins, privileged access, unusual geographies, and elevated-risk transactions. Those are the points where phishing, adversary-in-the-middle attacks, and session theft are most likely to turn a valid password into an account takeover. In practice, the key adds a stronger proof of presence than a password alone can provide.
The password still matters because it is often the widest compatibility layer in the account stack. Passwords are used for first registration, backup access, account recovery, and sometimes for systems that have not adopted phishing-resistant authentication. That means a team cannot “upgrade” to keys without also deciding how resets, support requests, lost-device cases, and emergency access will work.
Implementation guidance from the Workforce Identity Security Guide is directly relevant here because it covers phishing-resistant MFA, security keys, account recovery, and step-up authentication in the same operating model. For teams managing shared or service-style accounts, the Service Account Security Guide is the better companion when the issue is not human sign-in but credential governance and privileged access.
What “good” looks like in an account protection policy
Good practice is not “use a key everywhere” or “use a password everywhere,” but a layered policy that matches risk. Low-risk access can stay on a password plus ordinary secondary factor, while higher-risk access should require a key, preferably with phishing-resistant prompts for privileged or sensitive sessions. The account should still have a recovery path, but that path should be more controlled than the everyday login path.
The strongest pattern is to combine unique passwords, a password manager, and a security key for interactive sign in. That combination reduces remote takeover risk while preserving a fallback if the key is lost or a user migrates devices. The common failure is to introduce keys without tightening recovery, because attackers then target the weakest remaining process rather than the primary login screen.
The MFA Guide helps teams compare where security keys outperform weaker MFA methods, and the Ivanti Connect Secure exploitation 2024 case is a reminder that exposed credentials are often only the starting point; once an attacker gets a foothold, passwords, tokens, and other secrets can become part of the blast radius.
Risk and Threat Considerations
Security keys reduce phishing and remote replay risk, but they do not eliminate account takeover when passwords stay weak, reused, or recoverable through poor support processes. The main exposure is that attackers shift from the login prompt to password reset, help desk abuse, legacy authentication, or any flow where the key is bypassed or not checked.
Failure mechanism: An attacker obtains or guesses the password, then uses an alternate path such as recovery, fallback MFA, or a legacy sign-in route that does not enforce the key. If the password is reused elsewhere, credential stuffing and password spraying can also turn one exposed secret into multiple account compromises.
Impact: The account can still be taken over, especially when sign-in is tied to email, cloud services, or privileged administration. The presence of a security key lowers the attack rate, but it does not protect weak recovery logic or bad password discipline.
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, OWASP ASVS and CIS Controls v8 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST SP 800-53 Rev 5 | IA-2 — Identification and Authentication (Organizational Users) | Passwords plus security keys govern how users authenticate to accounts. |
| IA-5 — Authenticator Management | The question depends on password hygiene, key handling, and recovery planning. | |
| IA-9 — Service Identification and Authentication | Security keys and passwords help distinguish human sign-in from other authenticated access paths. | |
| Recommendation — Require strong authentication for user sign-in and step-up access. Manage password, token, and key lifecycle with controlled issuance, rotation, and revocation. Apply separate authentication controls where accounts or services authenticate non-interactively. | ||
| NIST SP 800-63 | IAL — Identity Assurance Level | Security keys are relevant to phishing-resistant authentication strength and recovery design. |
| Recommendation — Set assurance and recovery requirements that match the risk of the account. | ||
| OWASP ASVS | V6 — Authentication | The topic is about strengthening login with a second factor and resilient recovery. |
| Recommendation — Verify phishing-resistant authentication and recovery requirements for protected accounts. | ||
| CIS Controls v8 | CIS-6 — Access Control Management | Using keys alongside passwords is an access-control decision about who can sign in and when. |
| Recommendation — Enforce stronger authentication for higher-risk access paths and privileged accounts. | ||
Practitioner Guidance
What to verify: Confirm that the security key is required for the sign-in paths that matter most, and that fallback or recovery routes are at least as strong as the normal login path. If recovery can be completed with only a guessable password, the key is not providing the level of protection the policy implies.
Decision rule: If the account can reach sensitive systems, privileged actions, or high-value data, keep the password strong and unique, then require the key for step-up or high-risk authentication. If the workflow cannot support key enforcement, treat that as a control gap and not as a reason to rely on the password alone.
Practitioner takeaway: The real objective is to make password compromise insufficient on its own, while ensuring that recovery, fallback, and support processes do not quietly erase the benefit of the key.
Related resources from NHI Mgmt Group
- How do security teams decide whether to use OIDC federation or service-account keys for MCP access?
- How should security teams reduce account takeover risk when employees still use passwords across SaaS apps?
- How should security teams use device intelligence to reduce account takeover risk without relying only on passwords or MFA?
- How should security teams detect cloud account abuse when attackers use valid AWS access keys to create persistence?
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on September 28, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
