Home About Tools Projects Guides & Blog ⚡ Hire Me ✦ Websites Contact →
🔒 Cybersecurity

Passwordless Authentication with FIDO2 and Windows Hello for Business

Passwords are the weakest link in most authentication chains. They get phished, reused, stolen in data breaches, and brute-forced. Passwordless authentication eliminates the password entirely - replacing it with something you have (a hardware key or device) and something you are (biometrics or a PIN tied to that device).

Microsoft supports three main passwordless methods: Windows Hello for Business, FIDO2 security keys, and the Microsoft Authenticator app. This guide covers how to deploy Windows Hello for Business and FIDO2 keys through Intune and Entra ID.

Why Passwordless?

🔍 Overview

Traditional MFA (password + authenticator code) still leaves you vulnerable to real-time phishing attacks where an attacker proxies both the password and the MFA code simultaneously. Passwordless methods using cryptographic keys are phishing-resistant by design - the private key never leaves the device, so there is nothing to steal or proxy.

  • Windows Hello for Business: replaces the password at Windows sign-in with a biometric (face/fingerprint) or PIN, backed by a device-bound cryptographic key in the TPM
  • FIDO2 security keys: physical USB/NFC keys (YubiKey, etc.) that store a cryptographic key. Touch the key to authenticate - works for both Windows sign-in and web apps
  • Microsoft Authenticator: phone-based passwordless using biometrics on the phone, backed by a key pair registered to your Entra ID account

Part 1: Windows Hello for Business

🔐 Windows Hello

Windows Hello for Business (WHfB) is the primary passwordless method for domain-joined Windows devices. Once enrolled, users sign into Windows using their face, fingerprint, or a device-specific PIN - with the password locked away and never used for authentication.

Enable via Intune Policy

⚠️
Tenant-wide vs policy-based
The Windows Hello for Business settings in the Enrollment section apply tenant-wide to all Intune-enrolled devices. For more granular control (applying to specific groups), use an Identity Protection configuration profile instead. The tenant-wide setting takes precedence if enabled.
🔐
Windows Hello for Business: Recommended
Enrolment settings (applies tenant-wide)
Configure Windows Hello for Business
Enabled
Minimum PIN length
6
Maximum PIN length
127
Lowercase letters in PIN
Allowed
Uppercase letters in PIN
Allowed
Special characters in PIN
Allowed
PIN expiry (days)
Never (0)
Remember PIN history
5
Enable PIN recovery
Enabled
Use a Trusted Platform Module (TPM)
Required
Allow biometric authenticationEnables Windows Hello face and fingerprint recognition.
Enabled
Use enhanced anti-spoofing when available
Enabled
Allow phone sign-in
Disabled

User Experience

After the policy applies, users are prompted to set up Windows Hello during their next sign-in. They verify their identity with their existing MFA method, then enrol their biometric or PIN. From that point on, they sign into Windows with their face, fingerprint, or PIN - no password entered at the Windows lock screen.

Part 2: FIDO2 Security Keys

🔑 FIDO2

FIDO2 security keys (YubiKey, Feitian, etc.) are physical hardware authenticators. They are the gold standard for phishing-resistant MFA - the private key is stored on the key and never leaves it. They work for Windows sign-in, web browsers, and any app that supports WebAuthn.

Enable FIDO2 in Entra ID

🔑
FIDO2 Security Key Policy
Entra ID Authentication Methods
Enable
Yes
TargetStart with a pilot group, then expand to all users.
Select users / All users
Allow self-service set up
Yes
Enforce attestationRestricts to FIDO2 keys with verifiable manufacturer attestation. Recommended for high-security environments.
No (unless high-sec)
Enforce key restrictions
No (or specify allowed AAGUIDs)

Enable FIDO2 Sign-in on Windows

To allow users to sign into Windows devices with a FIDO2 key, enable this setting in an Intune device configuration profile:

🔑
FIDO2 Windows Sign-in Settings
Settings Catalog: Authentication
Enable Web Sign In for WindowsAllows browser-based FIDO2 authentication at the Windows lock screen.
Enabled
Use Security Key For Signin
Enabled

User Enrolment

Users register their FIDO2 key at mysignins.microsoft.com → Security info → Add sign-in method → Security key. They plug in the key, touch it to confirm, set a PIN for the key, and it's registered.

Enforce Passwordless with Conditional Access

🔒 Enforcement

Once users are enrolled, you can enforce passwordless-only sign-in using a Conditional Access policy with Authentication Strength:

🔒
Conditional Access: Passwordless MFA
Require phishing-resistant authentication
UsersApply to your pilot group initially, then expand.
Passwordless pilot group
Target resources
All cloud apps
Grant → Authentication strength
Phishing-resistant MFA

The built-in Phishing-resistant MFA authentication strength covers Windows Hello for Business, FIDO2 keys, and certificate-based auth - all the hardware-bound methods that cannot be phished.

Recommended rollout approach
Start with a pilot group of 5–10 willing users. Enable both WHfB and FIDO2, let them use passwordless for a few weeks, then gather feedback before expanding. Use Conditional Access in report-only mode first to see the impact before enforcing. Once rolled out to all users, consider using Identity Protection to flag any remaining password sign-ins for review.
J
Jack Davies
IT Engineer · M365 & Intune Specialist

Jack is an IT Technical Engineer based in the UK, working day-to-day with Microsoft 365, Intune, and Entra ID across a range of businesses. He holds the MS-900 certification and is studying for a BSc in Cyber Security through the Open University. Outside of work he builds and documents home lab projects, writes guides on this site, and takes on M365 consulting work for small businesses.

About Jack → LinkedIn →
// monthly tips

Get M365 tips in your inbox

Practical Intune and Microsoft 365 tips, once a month. No spam, no fluff.