Skip to content
AI Security

Interview question · Identity, OAuth & Access Control

Walk through WebAuthn registration and authentication. What makes passkeys phishing-resistant, and what does attestation add?

The user never types anything an attacker could replay, and the browser, not the user, decides which site is asking. Those two facts are the whole phishing story; the ceremony is how they are enforced.

hardEssentialNewPreparation tags: Google, Apple, MicrosoftUpdated Nov 2026

The user never types anything an attacker could replay, and the browser, not the user, decides which site is asking. Those two facts are the whole phishing story; the ceremony is how they are enforced.

Make your first attempt

What would you say before reading the answer?

  1. 01 State the assumptions your answer depends on.
  2. 02 Explain the mechanism and choose a control.
  3. 03 Name a condition that would change your decision.

The worked answer includes an approach, scoring criteria and follow-up questions. Compare the reasoning with your own.

10 answers per topic instead of 5, plus saved progress and bookmarks · costs nothingor unlock all 529 remaining answers · $25

Every worked answer in all 17 topics, every lesson in every course, the full concept curriculum, the complete practice-test bank, and the downloadable security field guides.

6 months · One payment · No auto-renewal

What if · the follow-ups in this answer

The answer works through 6 follow-ups like an interviewer would

You are implementing passkey login for a consumer web app and must decide what the server checks during registration and authentication.

  1. What happens during registration?
  2. What happens during authentication?
  3. What must the server verify?
  4. What about the signature counter and synced passkeys?
  5. How should account recovery work?
  6. What would your implementation check?

Each rung has a nudge, a model answer, the principle that carries over and the weak answer to avoid. Premium opens every answer and ladder.

UP NEXT ON YOUR JOURNEY
Next in this trackHow do secret managers work: authenticating workloads, dynamic secrets with leases, rotation, and solving the 'secret zero' problem?Next in this trackHow does secret scanning work (patterns, entropy, validity checks, push protection), and what should happen when a secret leaks?Next in this trackHow do deepfakes defeat remote identity verification, and what is the difference between presentation and injection attacks?
DISCUSSION · 0

No comments yet. Share a correction or a different way to answer it.