How should security teams verify users for high-risk actions instead of OTP?

Why This Matters for Security Teams

OTP is still common because it is easy to deploy, but it does not reliably prove that the legitimate user is present. For high-risk actions such as payouts, privilege changes, recovery enrollment, or device binding, security teams need verification that resists phishing, token replay, and account takeover. That is why current guidance increasingly favors phishing-resistant authentication and step-up checks grounded in identity assurance, not just code entry.

The gap is especially visible in incident response. Once an attacker controls a mailbox, session, or SIM, OTP often becomes another approval channel rather than a real safeguard. NIST’s NIST Cybersecurity Framework 2.0 emphasizes outcome-based control design, while NHIMG research on why NHI security matters now shows how quickly weak identity controls become operational risk when trust is misplaced. In practice, many security teams discover OTP failure only after an attacker has already used the same recovery path that was meant to stop the breach.

How It Works in Practice

For high-risk actions, the better pattern is to verify a person through stronger proof, then bind that proof to the action being requested. In practice, that means phishing-resistant MFA such as FIDO2 or passkeys, plus context-aware step-up checks when the request is unusual. Security teams should treat OTP as a low-assurance fallback, not the primary control for sensitive workflows.

A practical design usually combines three layers:

• Phishing-resistant authentication for the initial sign-in or re-authentication event.
• Risk-based prompts that inspect device posture, location anomalies, transaction value, and prior behaviour before approving the action.
• Recovery flows that avoid the same compromised channel, such as the same inbox, phone number, or session that an attacker may already control.

For web and workforce environments, NIST SP 800-53 Rev. 5 and NIST SP 800-207 Zero Trust Architecture both support continuous evaluation rather than one-time trust. NHIMG’s Top 10 NHI Issues also aligns with the same operational lesson: the weakest authentication path often becomes the compromise path, especially when recovery is easier than primary login. Teams should also separate verification for identity proofing from authorisation for the action itself, because a strong login does not automatically justify a sensitive change. These controls tend to break down when legacy identity providers force SMS or email fallback because the fallback channel inherits the same compromise as the original session.

Common Variations and Edge Cases

Tighter verification often increases user friction and support overhead, requiring organisations to balance security against recovery speed and business continuity. That tradeoff is real, especially for executive approvals, customer support escalations, and fraud-sensitive operations where false rejects can delay legitimate work.

Best practice is evolving on how much step-up is enough. Some environments rely on a second phishing-resistant factor plus liveness checks, while others add out-of-band approval, device binding, or supervisor confirmation for especially sensitive actions. There is no universal standard for this yet, so the right threshold depends on the action’s impact and the attacker’s likely path. High-risk transactions should generally require a fresh, short-lived verification event, not a remembered session or a code that can be intercepted.

For regulated or high-trust environments, teams should also harden recovery. If account reset can be completed through the same phone number, email, or help desk workflow that an attacker can socially engineer, OTP is not the real problem, recovery is. NHIMG’s State of Non-Human Identity Security highlights how confidence gaps persist when identity controls are not matched to actual risk, and the same lesson applies to human verification. In practice, the failure mode appears when organisations optimise for convenience first and discover that “step-up” still routes through compromised channels.

Related resources from NHI Mgmt Group

• How should security teams verify proof of address in high-risk onboarding flows?
• How should security teams verify high-risk requests when deepfakes and voice cloning are in play?
• How should security teams implement step-up for high-risk actions?
• How should security teams implement dual control for high-risk identity actions?