Zero Trust Soldier

Jeg tar her opp tre spørsmål med ChatGPT:

• «Why should I add fido2 keys on top of a good windows hello for business implementation with biometric login?»
• «How does FIDO2 become phishing resistant? How does it kill an adversary the middle attack from succeeding?»
• «How would you compare WHfB vs FIDO2 token vs passkeys on a mobile phone being able to scan QR codes and more. There will be a cost with FIDO2 keys.»

«Why should I add fido2 keys on top of a good windows hello for business implementation with biometric login?»

That’s a sharp question—Windows Hello for Business (WHfB) with biometrics is already strong. But adding FIDO2 security keys can still bring additional layers of security, flexibility, and resilience. Here’s a breakdown of why it’s a smart move to complement WHfB with FIDO2 keys:

1. Resilience & Recovery

Use case: What if the biometric device fails (e.g., fingerprint reader breaks) or you’re using a loaner device? FIDO2 keys act as a portable, hardware-based login method that works even if your main device is unavailable. They’re great for account recovery or as a backup when WHfB isn’t available.

2. Cross-Platform Support

WHfB is tightly integrated with Windows, but FIDO2 keys can be used: Across browsers On Linux, macOS, Android, iOS For web apps like Office 365, Google Workspace, GitHub, etc. So, if you’re using Azure AD or Entra ID, you get broader single sign-on (SSO) reach with FIDO2.

3. True Portable Identity

With a FIDO2 key, the credential is stored on the hardware token—not tied to a device. Ideal for roaming users, contractors, or shared workstation environments.

4. Phishing Resistance

Both WHfB and FIDO2 are phishing-resistant, but FIDO2 can be used on more external services, especially ones exposed over the internet. It cryptographically binds the login to the origin, so credentials can’t be reused on fake sites.

5. Regulatory or Policy Compliance

Some orgs require multi-factor authentication with separate physical factors. A biometric login and a FIDO2 key together can meet stricter requirements like those from: NIST 800-63B (AAL3) CMMC FIPS 140-2 validated tokens (if required)

6. Temporary or Emergency Access

You can provision a FIDO2 key to a helpdesk or admin as a “break glass” login method in case WHfB isn’t working.

When You Might Not Need It

If your environment is 100% Windows 10/11, tightly managed, and you have:

• High device availability
• Low support burden
• No cross-platform or web-first needs

Then WHfB with biometrics might be sufficient alone. But for most enterprise scenarios, a hybrid approach is the most resilient and secure.

«How does FIDO2 become phishing resistant? How does it kill an adversary the middle attack from succeeding?»

FIDO2 is phishing-resistant because it uses public key cryptography and origin binding, which make it impossible for an attacker to trick a user into handing over credentials they can reuse.

Here’s how it works and how it defeats adversary-in-the-middle (AitM) attacks:

1. Key Pair Per Site (No Shared Secrets)

• During registration, your FIDO2 authenticator (like a security key) generates a unique public-private key pair for each website (relying party).
• The private key stays on the key, and the public key is stored with the site.

Why it matters: Even if you’re tricked into visiting a fake site, your FIDO2 key won’t use the private key because the fake site doesn’t match the original site’s origin.

2. Origin Binding (Relying Party ID / Facet Binding)

• The authenticator checks the website’s origin (domain) before responding.
• For example: If the key was registered to login.microsoft.com, it won’t respond to login-microsoft.fake.com.

AitM attack blocked: Even if an attacker proxies the session, they can’t trick the key into signing for the wrong domain.

3. User Presence & Verification

• The user must physically interact with the device (touch the key, scan a fingerprint).
• This ensures a real person is present and prevents silent use of credentials.

Attack blocked: The attacker can’t trigger a login or sign something silently in the background.

4. No Passwords to Steal

• Since no password is entered, there’s nothing to phish.
• Credentials are bound to the device and can’t be exfiltrated or reused.

Summary: Why AitM Fails Against FIDO2

FIDO2 is like a GPS-locked missile—it only fires if it’s on the right target (verified origin) and with a human in the loop (user presence).

«How would you compare WHfB vs a FIDO2 token vs passkeys on a mobile phone being able to scan QR codes and more. There will be a cost with FIDO2 keys.»

Excellent topic—you’re on the right track. Comparing Windows Hello for Business (WHfB), FIDO2 hardware tokens, and mobile-based passkeys (like QR-enabled login on smartphones) is essential for designing modern, phishing-resistant authentication strategies. Let’s break down the trade-offs in depth.

1. Windows Hello for Business (WHfB)

Strengths:

• Tightly integrated into Windows + Azure AD/Entra ID.
• Uses TPM-based key storage and strong biometrics (fingerprint, facial recognition).
• Phishing-resistant: Authenticates to the correct identity provider using keys bound to the device.

Limitations:

• Tied to a specific device—no portability.
• Doesn’t work well cross-platform (e.g., macOS, Android, web apps).
• Recovery requires a well-designed enterprise process (e.g., self-service reset, reprovisioning).

2. FIDO2 Hardware Tokens (e.g., YubiKey, SoloKey)

Strengths:

• Phishing-resistant: Enforces origin binding.
• Fully portable, ideal for roaming users and shared device environments.
• Cross-platform: Works on Windows, macOS, Linux, iOS, Android, browsers.
• Ideal for break-glass access, admins, or contractors.

Limitations:

• Cost per user (hardware tokens range from $20–$80).
• Logistical overhead: shipping, provisioning, recovery if lost.
• Requires physical interaction (touch or PIN) and USB/NFC compatibility.

3. Mobile-Based Passkeys (via phone, QR code, Bluetooth, etc.)

Strengths:

• Based on FIDO2/WebAuthn standards.
• Phones store passkeys in secure hardware (e.g., iOS Secure Enclave, Android StrongBox).
• Allows QR code login or Bluetooth proximity authentication—device can act as an authenticator.
• Free to deploy (no hardware cost).
• Syncs across devices via iCloud Keychain or Google Password Manager.

Limitations:

• Currently relies on platform ecosystems (e.g., Apple → Apple devices).
• Passkey syncing introduces a trust boundary—a risk in high-assurance environments.
• If a phone is lost/stolen, recovery depends on cloud account access (a new potential attack surface).

Phishing Resistance (All Strong, with Nuance)

Cost & Deployment Summary

Decision Criteria (When to Use What)

Hvordan fungerer FIDO2?

Jeg vil anbefale å lese delen om QR koder.

https://michaelwaterman.nl/2025/04/02/how-fido2-works-a-technical-deep-dive/