What does passkey mean?
A passkey is a sign-in credential that replaces a password with a pair of cryptographic keys: the private key stays on your device and is used only after you approve with a fingerprint, face or PIN, while the website stores the public key. Nothing secret is typed or sent, so a fake site has nothing to steal.
Passkeys are a passwordless sign-in method built on the FIDO2 and WebAuthn standards, in which a user's device holds a private cryptographic key and the service holds the matching public key. To sign in, the user approves the request on the device with a fingerprint or a device PIN, and the device proves possession of the key without ever transmitting a secret that could be stolen or reused.
When a passkey is created, the device generates a unique key pair for that specific website or application and registers the public half with the service. At each login the service sends a random challenge; the device signs it with the private key after the user approves, and the service verifies the signature. Two properties make this resistant to phishing. The private key never leaves the device, so there is nothing to intercept. And the passkey is bound to the exact web address it was created for, so a look-alike site cannot trigger it no matter how convincing the page looks. Passkeys can be device-bound, living only on a hardware security key or a specific computer, or synced through a platform account so they follow the user across phones and laptops. Microsoft Entra ID supports both forms, including passkeys stored in the Microsoft Authenticator app.
For a small or mid-sized business passkeys close the gap left by ordinary multi-factor authentication. Push notifications and one-time codes can be phished with a fake login page that relays the code in real time, or worn down by repeated prompts until a tired employee taps approve. A passkey cannot be relayed. The transition is gradual: start with administrators and finance staff and keep a recovery path for lost devices. Some older applications will need single sign-on through Entra ID before they can use passkeys at all.
NetSys rolls out passkeys through its multi-factor authentication service, beginning with the accounts that attackers value most and using Entra ID authentication strength policies to require phishing-resistant methods for administrator roles and sensitive applications. Recovery procedures are documented before enforcement, and the change is paired with conditional access so a stolen password alone is never enough.
Why it matters for a small business
Most of the account takeovers that hit small businesses today defeat ordinary multi-factor authentication, either by phishing the code or by pestering the user with prompts until one is approved. Passkeys end both tactics because there is no code to steal and no prompt to approve from a fake site. For an owner that means the finance team's email and the administrator accounts can be protected in a way that does not depend on anyone spotting a convincing forgery. Users tend to like them, too: a fingerprint is faster than a password plus a code, and there is nothing to remember or reset.
Where NetSys handles this
Passkeys: FAQs
What is a passkey and how does it work?
A passkey is a login credential that replaces a password with a pair of cryptographic keys. The private key stays on your device, protected by your fingerprint or PIN, and the public key is stored by the website or application. When you sign in, the service sends a challenge, your device signs it after you approve, and the signature proves it is you. Nothing secret is typed or sent, so there is nothing for a phishing site to capture.
Are passkeys more secure than multi-factor authentication?
Passkeys are a form of multi-factor authentication, and they are more secure than the common kinds. Codes sent by text or generated by an app, and push approvals, can all be phished through a fake login page that relays them in real time or defeated by repeated prompts. A passkey is bound to the real site's address and never exposes a secret, so a look-alike page cannot use it. CISA describes FIDO-based methods, including passkeys, as phishing-resistant for this reason.
Do passkeys work with Microsoft 365?
Yes. Microsoft Entra ID supports passkeys stored in the Microsoft Authenticator app on iOS and Android, as well as passkeys on FIDO2 hardware security keys, and administrators can require them through authentication strength policies in Conditional Access. Users register a passkey from their security settings and then sign in to Microsoft 365 by approving on their phone or touching a key. Password-based sign-in can be phased out for specific groups once passkeys are in place and a recovery process exists.
What is passkey authentication?
Passkey authentication is signing in with a passkey instead of a password. The site sends a one-time challenge, your device asks you to confirm with a fingerprint, face or PIN, then signs the challenge with the private key, and the site checks the signature against the public key it saved when you registered. It is built on the FIDO2 and WebAuthn standards, which Windows, Apple and Android devices support.
What is a physical passkey?
A physical passkey is a passkey stored on a hardware security key, a small USB, NFC or Bluetooth device built to the FIDO2 standard. The private key never leaves that device, which makes it a strong choice for administrators and finance staff, and Microsoft Entra ID accepts FIDO2 security keys for Microsoft 365 sign-in. Register a second key as a spare in case the first is lost.
What is a Windows security passkey?
It usually means a passkey saved on a Windows PC and protected by Windows Hello. When a website asks for your passkey, Windows prompts you to confirm with your face, fingerprint or PIN, and on Windows 11 you can view or delete saved passkeys under Settings, Accounts, Passkeys. Windows can also use a passkey stored on your phone or on a security key for the same sign-in.
More terms
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