Retailers should remove passwords, add phishing-resistant MFA, and keep the flow simple enough that customers can complete purchases without friction. The right balance is security that uses strong factors such as biometrics or device possession, plus clear messaging and low-burden recovery. If authentication becomes an obstacle, shoppers abandon carts and attackers exploit weaker fallback paths.
Why phishing-resistant authentication helps, but cannot be the whole checkout design
Retail checkout is a conversion-sensitive workflow, so the authentication pattern has to be strong enough to stop account takeover while still feeling almost invisible to legitimate shoppers. That usually means replacing knowledge-based factors with phishing-resistant methods such as device-bound authenticators, passkeys, or biometrics, then keeping session steps short, predictable, and mobile-friendly. The core design goal is to reduce fraud without adding avoidable abandonment.
The practical trade-off is that stronger authentication often shifts friction rather than removing it. Customers may tolerate one high-assurance step at account creation or payment authorization, but they are far less forgiving of repeated prompts, confusing recovery, or login loops during a high-intent purchase. A good checkout flow therefore treats authentication as a risk-based control point, not a blanket obstacle at every interaction.
Retailers also need to distinguish between authenticating the customer and authenticating the transaction. For many shoppers, especially during peak season, it is better to preserve a low-friction browse and cart experience, then apply stronger verification only when the transaction becomes materially risky, such as new-device checkout, account changes, address edits, unusual basket value, or gift card abuse patterns.
How to reduce checkout friction without weakening the control
The best balance comes from designing around the points where users already expect a security step. If a shopper has a trusted device or an existing authenticated session, let the flow continue with minimal interruption. If the environment is unfamiliar or the purchase is high-risk, use a step-up method that is still phishing-resistant and preferably reusable across visits, such as passkeys or device possession with biometric unlock.
During peak shopping seasons, retailers should focus on three implementation choices that have the biggest conversion impact: keep recovery low-burden, avoid repeated reauthentication inside the same session, and make fallback paths materially harder to abuse than the primary path. In practice, that means customers should not be pushed toward SMS-only recovery, legacy passwords, or manual support unless the risk is exceptional and the stronger path has genuinely failed.
Messaging matters as much as the control itself. Customers are more likely to complete checkout when the reason for the security step is clear, the screen is branded and familiar, and the user knows whether the prompt is part of the purchase or part of fraud prevention. Retailers that test authentication wording, device prompts, and recovery handling before peak season usually see better completion rates than those that treat authentication as a pure technical upgrade.
Risk and Threat Considerations
Peak shopping seasons compress attention, increase transaction volume, and give attackers more opportunities to exploit weak recovery, stale sessions, and fallback channels. If the primary authentication path is too rigid, users abandon carts; if the fallback path is too weak, attackers pivot into account takeover, payment abuse, or points and gift card theft.
Failure mechanism: The control fails when phishing-resistant authentication is added without redesigning the rest of the checkout journey, so customers bypass it, reuse weak recovery, or hit support-based exceptions that are easier to social-engineer than the primary flow.
Impact: Retailers get the worst of both worlds, higher abandonment for legitimate buyers and a broader attack surface for fraudsters, especially where the fallback path is weaker than the main login or checkout step.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Agentic AI Top 10 address the attack and risk surface, while NIST SP 800-63, CIS Controls v8 and NIST CSF 2.0 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST SP 800-63 | Phishing-resistant authenticators — Phishing-Resistant Authentication | Directly addresses phishing-resistant customer authentication and authenticator assurance. |
| Recommendation — Use phishing-resistant authenticators such as passkeys or WebAuthn to reduce phishing and replay risk. | ||
| CIS Controls v8 | 5 — Account Management | Checkout authentication depends on account lifecycle, recovery, and controlling valid customer access paths. |
| Recommendation — Harden account and recovery paths so weak fallback methods do not undermine stronger authentication. | ||
| NIST CSF 2.0 | PR.AA — Identity Management, Authentication, and Access Control | Covers authentication and access decisions that shape checkout security and user friction. |
| Recommendation — Apply identity and access controls that balance strong authentication with usable customer journeys. | ||
| OWASP Agentic AI Top 10 | A2 — Identity and Access Abuse | Relevant where attackers exploit weak fallback or session handling around customer auth flows. |
| Recommendation — Prevent fallback abuse by ensuring alternative checkout paths are not easier to subvert than the primary control. | ||
Practitioner Guidance
What to prioritise: Protect the highest-risk moments first, not every screen equally. Step-up authentication is most valuable when the transaction changes risk materially, such as account takeover signals, new devices, address changes, or unusually high-value baskets.
What to verify: Before peak season, test the full path for trusted devices, account recovery, guest checkout, and support escalation. If any of those paths can be used more easily than the phishing-resistant route, the design is not balanced yet.
Decision rule: If a control makes legitimate shoppers restart, re-enrol, or contact support during checkout, treat that as a conversion defect as well as a security issue. If it only adds a single, familiar confirmation step at the right moment, it is much closer to the right trade-off.
Practitioner takeaway: The goal is not maximum authentication everywhere, it is the strongest possible control at the narrowest point that still preserves purchase completion and closes the weakest fallback path.
Related resources from NHI Mgmt Group
- How should merchants balance fraud prevention with customer-friendly returns policies during peak holiday shopping periods?
- How should online retailers optimise checkout for mobile devices to reduce payment fraud during peak shopping periods?
- How should payment organisations implement strong customer authentication without creating unnecessary checkout friction?
- How should teams balance phishing-resistant authentication with legacy on-premises systems that still need older login methods?
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on September 20, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
