FIDO Study Guide 2026
Everything you need to pass the FIDO exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 FIDO Exam Format at a Glance
📚 FIDO Topics to Study (69)
✍️ Sample FIDO Questions & Answers
1. A FIDO relying party wants to mitigate the risk of a stolen authenticator being used by an unauthorized person. Which control is most effective?
Requiring user verification (PIN or biometric) ensures that possession of the device alone is not sufficient to authenticate.
2. Which cryptographic primitive is used by FIDO2 authenticators to prove possession of a private key without revealing it?
FIDO2 authenticators use digital signatures (e.g., ECDSA or EdDSA) to prove private key possession during authentication assertions.
3. What is the role of the 'aaguid' field in a FIDO2 attestation statement?
The AAGUID (Authenticator Attestation GUID) is a 128-bit identifier that identifies the type (make and model) of the authenticator.
4. A FIDO server team tracks 'mean time to detect' (MTTD) attestation verification failures. Reducing MTTD is an example of improving which quality dimension?
Detectability measures how quickly issues are found; improving MTTD means the system surfaces failures faster, enabling quicker remediation.
5. What role does attestation play in device security?
Attestation in FIDO plays a crucial role in device security by providing proof of the authenticator's legitimacy and characteristics to the relying party. It allows the server to verify that the FIDO authenticator is a genuine, trusted device and has not been tampered with. This process enhances security by ensuring that only compliant and secure devices are used for authentication, preventing the use of malicious or compromised authenticators.
6. What is the purpose of the 'largeBlobKey' extension in CTAP2.1?
The largeBlobKey extension provides a symmetric key unique to each credential, used to encrypt and authenticate large blobs stored on the authenticator.