FIDO Cheat Sheet 2026

The 30 highest-yield FIDO facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What are potential consequences of regulatory non-compliance for FIDO Certified Authenticator professionals? → Fines, license revocation, legal liability, and reputational damage
2. Which of the following is NOT one of the defined WebAuthn attestation statement formats? → fido-u2f-legacy
3. What is the significance of a code of ethics for FIDO professionals? → It establishes expected behaviors that protect both the public and the profession
4. What is the primary purpose of regulatory compliance in FIDO Certified Authenticator practice? → To protect public safety and maintain professional accountability
5. What is a risk register used for in FIDO Certified Authenticator practice? → Tracking identified risks with their status, controls, and owners
6. What enables compatibility among certified devices? → Standardized protocols
7. What is a corrective action in FIDO Certified Authenticator quality systems? → A systematic response to eliminate causes of nonconformity and prevent recurrence
8. What does an Authenticator Attestation GUID (AAGUID) uniquely identify? → A specific model and batch of authenticator from a particular manufacturer
9. Which cryptographic method is central to FIDO authentication? → Public key cryptography
10. Which component in a FIDO2 architecture is responsible for storing the credential public key after registration? → The Relying Party server
11. Why does FIDO support multiple verification methods? → To support diverse user needs
12. How should FIDO professionals apply research findings to practice? → Critically evaluate applicability, adapt to context, and monitor outcomes
13. What does the 'backup eligibility' (BE) flag in FIDO2 authenticator data indicate? → The credential is eligible to be backed up and synced to another device or cloud keychain
14. What is a key benefit of using public key cryptography in FIDO? → Enhances security with asymmetric keys
15. How should FIDO professionals evaluate new technology tools? → Assess functionality, reliability, security, and alignment with professional needs
16. What makes biometric data secure in FIDO? → Kept only on the local device
17. What role does documentation play in FIDO Certified Authenticator client communications? → It creates clear records of discussions, decisions, and agreements
18. What is the most effective communication approach for FIDO professionals? → Adapting communication style to the audience while maintaining accuracy
19. Which FIDO Authenticator Certification level requires the highest level of hardware security, including resistance to physical attacks? → Level 3 (L3)
20. How should FIDO professionals stay current with regulatory changes? → Actively monitor updates through professional associations and continuing education
21. What is the role of the relying party in FIDO? → Verifies authentication results
22. Why is documentation important in FIDO risk management? → It creates an audit trail and demonstrates due diligence
23. What is a fallback for biometric failure? → Use backup PIN or password
24. Which algorithm is commonly used in FIDO cryptographic operations? → ECDSA
25. How should an FIDO professional approach a novel situation not covered by standard procedures? → Apply foundational principles, assess risks, consult resources, and document decisions
26. What ensures the privacy of biometric authentication in FIDO? → On-device biometric processing
27. How does interoperability benefit users? → Enhances convenience and usability
28. What is a conformance test? → Functionality verification
29. What is the purpose of the 'excludeCredentials' parameter sent by the RP during a WebAuthn registration request? → To prevent duplicate credential registrations on the same authenticator
30. Why is biometric integration valuable in FIDO standards? → They boost usability and security