Implementing Passwordless Auth with Microsoft Entra

When to Use

• Organization wants to eliminate password-based attacks (phishing, credential stuffing, brute force)
• Regulatory or internal mandate requires phishing-resistant MFA (Executive Order 14028, CISA guidance)
• Deploying FIDO2 security keys or Windows Hello for Business across the enterprise
• Migrating from legacy MFA (SMS, phone call) to phishing-resistant authentication methods
• Implementing passkey support for hybrid or cloud-joined Windows devices
• Reducing helpdesk costs from password reset requests

Do not use for environments that cannot support modern authentication protocols; legacy applications using NTLM or basic authentication must be migrated first.

Prerequisites

• Microsoft Entra ID P1 or P2 license (Azure AD Premium)
• Windows 10/11 22H2+ for Windows Hello for Business deployment
• FIDO2-compliant security keys (YubiKey 5 Series, Feitian BioPass, Google Titan)
• Microsoft Authenticator app 6.8+ for passkey support on iOS 16+/Android 14+
• Hybrid Azure AD join or Azure AD join configured for Windows devices
• Conditional Access policies configured for authentication strength

Workflow

Step 1: Configure Authentication Methods Policy

Enable passwordless authentication methods in Microsoft Entra:

# Connect to Microsoft Graph
Connect-MgGraph -Scopes "Policy.ReadWrite.AuthenticationMethod", "User.ReadWrite.All"

# Enable FIDO2 Security Key authentication method
$fido2Policy = @{
    "@odata.type" = "#microsoft.graph.fido2AuthenticationMethodConfiguration"
    state = "enabled"
    isAttestationEnforced = $true
    isSelfServiceRegistrationAllowed = $true
    keyRestrictions = @{
        isEnforced = $true
        enforcementType = "allow"
        aaGuids = @(
            "cb69481e-8ff7-4039-93ec-0a2729a154a8",  # YubiKey 5 Series
            "ee882879-721c-4913-9775-3dfcce97072a",  # YubiKey 5 NFC
            "fa2b99dc-9e39-4257-8f92-4a30d23c4118",  # YubiKey 5C NFC
            "2fc0579f-8113-47ea-b116-bb5a8db9202a",  # YubiKey Bio
            "73bb0cd4-e502-49b8-9c6f-b59445bf720b"   # Google Titan
        )
    }
    includeTargets = @(
        @{
            targetType = "group"
            id = "all_users"  # Or specific security group ID
        }
    )
}
Update-MgPolicyAuthenticationMethodPolicyAuthenticationMethodConfiguration `
    -AuthenticationMethodConfigurationId "fido2" `
    -BodyParameter $fido2Policy

# Enable Microsoft Authenticator with passkey support
$authenticatorPolicy = @{
    "@odata.type" = "#microsoft.graph.microsoftAuthenticatorAuthenticationMethodConfiguration"
    state = "enabled"
    featureSettings = @{
        displayAppInformationRequiredState = @{
            state = "enabled"
            includeTarget = @{
                targetType = "group"
                id = "all_users"
            }
        }
        displayLocationInformationRequiredState = @{
            state = "enabled"
            includeTarget = @{
                targetType = "group"
                id = "all_users"
            }
        }
        companionAppAllowedState = @{
            state = "enabled"
        }
    }
    includeTargets = @(
        @{
            targetType = "group"
            id = "all_users"
            authenticationMode = "any"
        }
    )
}
Update-MgPolicyAuthenticationMethodPolicyAuthenticationMethodConfiguration `
    -AuthenticationMethodConfigurationId "microsoftAuthenticator" `
    -BodyParameter $authenticatorPolicy

# Enable Windows Hello for Business
$whfbPolicy = @{
    "@odata.type" = "#microsoft.graph.windowsHelloForBusinessAuthenticationMethodConfiguration"
    state = "enabled"
    pinMinimumLength = 6
    pinMaximumLength = 127
    pinLowercaseCharactersUsage = "allowed"
    pinUppercaseCharactersUsage = "allowed"
    pinSpecialCharactersUsage = "allowed"
    securityKeyForSignIn = "enabled"
    includeTargets = @(
        @{
            targetType = "group"
            id = "all_users"
        }
    )
}
Update-MgPolicyAuthenticationMethodPolicyAuthenticationMethodConfiguration `
    -AuthenticationMethodConfigurationId "windowsHelloForBusiness" `
    -BodyParameter $whfbPolicy

Write-Host "Passwordless authentication methods enabled successfully"

Step 2: Configure Authentication Strength Conditional Access

Create Conditional Access policies requiring phishing-resistant authentication:

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