# Transaction Authentication in Secure Card on File - Use Cases
source: https://developer.mastercard.com/mastercard-checkout-solutions/tutorial/authentication_scof_guide/index.md

Mastercard offers transaction authentication\*\* during checkout.

\*\* The authentication methods are available based on - regions, type of device and account.

## Authentication Methods {#authentication-methods}

### Passkey Authentication {#passkey-authentication-br}

FIDO (Fast Identity Online) uses cardholder's biometric for authentication on a FIDO-supported device.

### Issuer Authentication {#issuer-authentication-br}

Authentication driven by Issuer where the cardholders may be asked to verify their identity.   
Currently, Mastercard facilitates EMV 3DS.