In view of the approaching transition to mandatory support of EMV standard by US merchants, it is important for payment gateway software developers to understand the key features they need to add to their products to be able to make perform EMV integrations as smoothly as possible. Particularly, the EMV integration-related logic must include the functionality for exchange of data between a chip card, a terminal, and a gateway/processor. EMV standard is much more complicated than the one used in ordinary swipe credit cards.
There are several necessary fields, which have to be present in the request, when a transaction is submitted to the issuer. These fields include tag data from the chip and a set of fields, related to terminal’s EMV capabilities, card entry mode, etc. Just like a request, a response message must also include some mandatory fields. It should be stressed, that integrity of the outgoing data is ensured by special cryptograms, attached to request and response, respectively.
Finally, there is a list of mandatory fields, which must be printed on a receipt. Particularly, this requirement is intended to make the functioning of the system, which prints the receipt, more visible and transparent for developers. The common mandatory fields include application name, application PAN, card entry mode, transaction total, cardholder verification, authorization mode, and EMV tag data.
More information on host EMV integrations can be found in the respective article “Peculiarities of host EMV integrations” at Paylosophy.