First card action analysis
One of the data objects read from the card in the Read application data stage is CDOL1 (Card Data object List). This object is a list of tags that the card wants to be sent to it to make a decision on whether to approve or decline a transaction (including transaction amount, but many other data objects too). The terminal sends this data and requests a cryptogram using the generate application cryptogram command. Depending on the terminal′s decision (offline, online, decline), the terminal requests one of the following cryptograms from the card:
- Transaction certificate (TC)—Offline approval
- Authorization Request Cryptogram (ARQC)—Online authorization
- Application Authentication Cryptogram (AAC)—Offline decline.
This step gives the card the opportunity to accept the terminal's action analysis or to decline a transaction or force a transaction on-line. The card cannot return a TC when an ARQC has been asked for, but can return an ARQC when a TC has been asked for.