FIDO Device Security & Cryptographic Operations 1 — Questions and Answers

Question 1: What is the primary goal of device security in FIDO authentication?

To track user location
To monitor network speed
To secure authenticator operations (Correct answer)
To disable encryption

Correct answer: To secure authenticator operations

The primary goal of device security in FIDO authentication is to protect the operations of the authenticator itself. This involves safeguarding the cryptographic keys and the processes that use them, ensuring they cannot be compromised or tampered with. By securing the authenticator, FIDO prevents unauthorized access and ensures the integrity and trustworthiness of the entire authentication process.

Question 2: Which cryptographic method is central to FIDO authentication?

Hash encryption
Public key cryptography (Correct answer)
Block cipher
Data obfuscation

Correct answer: Public key cryptography

Public key cryptography, also known as asymmetric cryptography, is central to FIDO authentication. This method uses a pair of mathematically linked keys—a public key and a private key—where the private key is securely stored on the user's device and never leaves it. This architecture allows for strong, phishing-resistant authentication by signing challenges with the private key, which can then be verified by the public key.

Question 3: How is a private key stored in a secure authenticator?

In the cloud
On the browser cache
Within secure hardware (Correct answer)
In email drafts

Correct answer: Within secure hardware

In FIDO authentication, the private key is stored within secure hardware on the user's device, such as a Trusted Platform Module (TPM) or a secure element. This hardware-based storage provides a high level of protection against software attacks and physical tampering. Keeping the private key isolated and protected ensures it cannot be easily extracted or copied, which is fundamental to FIDO's security model.

Question 4: What operation uses the private key during authentication?

Decrypts the browser
Signs the challenge (Correct answer)
Creates the login page
Stores cookies

Correct answer: Signs the challenge

During FIDO authentication, the private key is used to digitally sign a challenge issued by the relying party (server). This signing operation proves possession of the private key without ever revealing the key itself. The server then uses the corresponding public key to verify the signature, confirming the user's identity and the authenticity of the device.

Question 5: What prevents a cryptographic key from being copied or exported?

Stored on public USB
Locked by PIN only
Bound to secure hardware (Correct answer)
Signed using HTTP

Correct answer: Bound to secure hardware

A cryptographic key is prevented from being copied or exported in FIDO by being securely bound to the hardware authenticator. This means the key is generated and stored within a secure element or TPM, designed to resist extraction and duplication. This hardware binding ensures that the private key never leaves the device, making FIDO authentication highly resistant to phishing and credential theft.

Question 6: Which algorithm is commonly used in FIDO cryptographic operations?

MD5
ECDSA (Correct answer)
DES
SHA1

Correct answer: ECDSA

Elliptic Curve Digital Signature Algorithm (ECDSA) is a commonly used algorithm in FIDO cryptographic operations. ECDSA is an efficient and secure public-key cryptographic algorithm used for generating digital signatures. Its use in FIDO ensures strong authentication by enabling the secure signing of challenges with the private key and verification with the public key, providing robust security with smaller key sizes.

Question 7: What role does attestation play in device security?

Verifies IP location
Authenticates login speed
Provides device legitimacy (Correct answer)
Sends SMS tokens

Correct answer: Provides device legitimacy

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.

Question 8: Which feature ensures cryptographic keys remain secure in FIDO devices?

Software logging
Hardware isolation (Correct answer)
Password rotation
Cookie syncing

Correct answer: Hardware isolation

Hardware isolation is a key feature that ensures cryptographic keys remain secure in FIDO devices. This means that the private keys are stored and operated within a secure hardware component, such as a secure element or TPM, which is physically and logically isolated from the main operating system. This isolation protects the keys from malware and other software-based attacks, making them extremely difficult to compromise.

Question 9: Why are symmetric keys not used for FIDO authentication?

They are too fast
They need complex passwords
They are easily shared (Correct answer)
They require OTP

Correct answer: They are easily shared

Symmetric keys are not used for FIDO authentication primarily because they rely on the same key for both encryption and decryption, making them easily shared and vulnerable to compromise if the key is exposed. FIDO's public key cryptography model, conversely, uses distinct public and private keys, ensuring the private key never leaves the user's device. This provides a much higher level of security against phishing and credential theft by eliminating the need to share a secret key.

FIDO Device Security & Cryptographic Operations 1

What is the primary goal of device security in FIDO authentication?