How to use Authy for Offline, Transaction Specific, PSD2 Compliant Authentication

To implement a compliant offline solution for PSD2 transactions, users can leverage Authy's Transactional TOTP feature. This involves generating a transaction string with specific parameters and encoding it in a QR code that the user scans using the Authy App. The Authy API is then used to verify the one-time password generated by the user, tying the transaction-specific information to the authentication event even when offline. By enabling Transactional TOTP on their Authy Application settings, users can ensure compliance with PSD2 regulations and secure their transactions.