Infosec glossary

Passkeys

Passkeys are often introduced as an easier sign-in experience, which is true but incomplete. They matter in security language because they change how credentials are created, stored, and used, and because they are tied closely to phishing-resistant authentication.

Operating principle 5 min read By Infosec Writing Studio editorial team Published Apr 18, 2026

What is Passkeys?

Passkeys are passwordless sign-in credentials built on public key cryptography. They let a user authenticate with a device-based credential, usually unlocked with biometrics or a PIN, instead of typing a traditional password.

Key takeaways

Passkeys are passwordless, but they are not the same thing as every passwordless method.
They are built to reduce phishing and credential theft risk.
The strongest explanations connect passkeys to public key authentication, not just convenience.
If the definition sounds like “log in with Face ID,” it is too consumer-shaped.

Common mix-ups

Treating passkeys as a synonym for biometrics.
Explaining passkeys as just a stored password replacement without mentioning public key cryptography.
Using passkeys and passwordless authentication as if they are identical terms.

Why passkeys matter in security terms

Traditional passwords remain one of the most fragile parts of identity security. Passkeys matter because they replace a reusable shared secret with a credential model designed to be harder to steal, replay, or phish.

That is why passkeys are not just a UX improvement. They are part of a more security-resilient authentication model.

How passkeys usually work

A passkey is created and stored on a trusted device or credential manager. When the user signs in, the device proves possession of the credential through a cryptographic exchange rather than sending a reusable password to the service.

The local unlock step may use biometrics or a PIN, but the key point is that the service is not receiving a password it can lose or store badly.

Public key-based sign-in
Device or manager-held credential
Local user verification
Reduced phishing exposure

How to explain passkeys clearly

Useful passkey explanations separate the user experience from the security model. The convenience angle is real, but the deeper point is that the credential structure itself is stronger than a password-first model.

The term becomes much clearer when it is placed next to passwordless authentication and phishing-resistant MFA without being collapsed into either one.

The term is clearer when the nearby language is clear too.

Use the pages below when you need adjacent terms, category context, or a longer explanation instead of leaving the definition to stand on its own.

Adjacent terms

Passwordless Authentication Phishing-Resistant MFA Zero Trust

Sources used to check the definition and terminology

FIDO Alliance reference for Passkeys

Open the external source used to verify the term's scope and related language.

Guides

Where the definition expands into a longer explanation

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