What is passkey?
How do passkeys work?
When creating the passkey, the authenticator geneated public and private keys and exchanged the key directly with the service provider or website
The private key will stay secret on your device only. When you try to log in, the server sends an encrypted message to the authenticator. The private key decrypts the message and sends the response back.
If the response message is verified, you will be signed in.