Push authentication is a secure and easy-to-use form of user authentication that allows companies to add useful context about the authentication event, such as payment information. It uses public key cryptography to link a single device to the user's identity, making it impossible for an attacker to impersonate them unless they have access to a registered device. Push authentication doesn't sacrifice user experience for more security and is being used by companies to replace passwords altogether. The Verify Push API helps companies quickly and securely deploy push authentication in their mobile apps, providing a high-enough level of protection that meets regulatory requirements like PSD2's strong customer authentication.