The ARes message is the Issuer's ACS response to the AReq message. It can indicate that the Cardholder has been authenticated, or that further Cardholder interaction is required to complete the authentication.

EMV 3DS is an e-commerce fraud prevention protocol that enables consumer authentication for CNP purchases, without adding unnecessary friction to the checkout process. How does EMV 3DS work? EMV 3DS helps payment card issuers identify unauthorised e-commerce transactions quickly and accurately to prevent CNP fraud.

How does 3D secure protection work? 3D Secure is an additional layer of card holder authentication on online card transactions. If a card holder is making a payment online and the bank detects that the transaction might be suspicious, the bank card issuer redirects them to a 3DS page for extra verification.

What is 3DS2? 3DS2 (3D Secure 2.0) is an authentication solution designed to protect customers when they shop online using credit or debit cards. The purpose of 3DS2 is specifically to prevent a shopper's credit or debit card from being used without their authorisation.