The Common Payment Application (CPA) specification V1.0 was published by EMV Co. after the Common Core Definition (CCD) had been defined in the latest published EMV 4.1. From the point of view of interoperability, it is unnecessary to define the application specification for implementation. But, the differences between the application specifications of different branded card have annoyed the issuer very much either for card issuance (personalization) or back-end processing. The objective of CPA is to provide a common payment application that not only comply with the EMV and CCD but also meet most requirements for current financial (payment) application. Based on the common internal processing flow and requirements, data element definitions, common personalization and so on, the issuer is possible to develop only one back-end system and purchase only one type of application chip card that comply with CPA for both Visa and MasterCard branded cards.
Some internal processing and new data elements definitions which are not included in EMV and CCD but used in CPA will be described in this article, which include:
1. Profile Selection and Profile Control
EMV have provided the possibility for chip card to switch into different operation mode according to the transaction environment. It is achieved by the card to ask the terminal to provide some transaction or terminal information identified in Processing Options Data Object List (PDOL) during Application Processing. CPA introduces the Profile Selection File to configure which operation mode shall be applied under what conditions. And the operation mode is specified by Profile Control.
2. VISA Low-Value Payment
VISA Low-Value Payment (VLP) is a special application which doesn’t appear in EMV specification. It is used for quick low-value transactions at some special transaction environment that supports the functionality.
3. Accumulator and Counter
The number of transactions or cumulative amounts for some transaction together with associated Lower (Upper) Count (Amount) limit are used for risk management in EMV. It is only a concept in EMV, but CPA realizes the concept into physical data elements and corresponding control mechanisms.
4. Cyclic Accumulator
Cyclic Accumulator is similar to Accumulator. The only difference is the accumulated value shall be reset after some cyclic time (daily, weekly or monthly).
5. Application Control and Issuer Options Profile Control
These two controls are used to control the behavior of the chip card application. The difference between these two controls is the Application Control is a global setting used to activate or deactivate some functions in the application, but the Issuer Options Profile Control is used to define the profile-specific behavior selected by the issuer for processing transactions under some conditions.
6. ADR and CIAC
What Issuer Action Code (IAC) and Terminal Action Code (TAC) are applied to Terminal Verification Result (TVR) is what Card Issuer Action Code (CIAC) to the Application Decision Result (ADR). The only difference is the previous one is used by terminal during the Terminal Risk Management, and the other one is used by card during the Card Risk Management.