> For the complete documentation index, see [llms.txt](https://yudu-sentinel.gitbook.io/sentinel-documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://yudu-sentinel.gitbook.io/sentinel-documentation/resources/profile-settings/passkeys.md).

# Passkeys

Introduction to Passkey Authentication

### What are Passkeys?

Passkeys are a modern, secure way to log in to your account — with no password required. Instead of typing a password, you simply use the same method you use to unlock your phone or computer: your fingerprint, face, or device PIN. It's faster, simpler, and significantly more secure than any password you could create.

{% hint style="info" %}
**Think of it like a house key — but better.** A traditional password is like a key you had to shout out loud every time you wanted to enter your house. Anyone nearby could hear it and copy it. A passkey is like a physical key that only works for your specific lock, never leaves your possession, and can't be duplicated — it's kept securely on your device and verified automatically.
{% endhint %}

***

### What are the Benefits?

#### Fast to use

Logging in takes a single tap or glance. No typing, no copying codes from an authenticator app — just verify and you're in.

#### Phishing-proof

Passkeys only work on the exact website they were created for. Even if you're tricked into visiting a fake site, your passkey simply won't work there.

#### Nothing to steal

Your private key never leaves your device. The server only holds a public key — which is useless to an attacker on its own.

#### Built-in second factor

Passkeys already prove both who you are (your device) and that it's really you (biometric or PIN). No separate two-factor step needed.

#### Works across your devices

Passkeys sync via iCloud Keychain, Google Password Manager, or a password manager like 1Password — so they're available on all your devices automatically.

####  More accessible

No need to remember passwords or follow complex creation rules. Users with memory difficulties or disabilities will benefit from the ease of biometric login.

***

### How does signing in with a Passkey work?

**Step 1 — You click "Sign in with passkey"** The site sends your device a challenge — a unique, one-time code — to prove your identity.

**Step 2 — Your device asks you to verify** You use your fingerprint, face scan, or PIN — exactly as you would to unlock your phone. This step stays entirely on your device.

**Step 3 — Your device signs the challenge** Using a private key stored securely on your device (which never leaves it), your device signs the challenge and sends the result back.

**Step 4 — The site verifies and logs you in** The server checks the signature using your public key. It matches, your identity is confirmed, and you're in — in under a second.