The CVV/CVC/CVV2/CVC2/CID/CVN values are verification values that are used to verify the integrity of the map data.
CVV – card verification value (VISA), CVC – card validation code (MasterCard), CID – Card Identification (American Express), CVN – card verification number (China Union Pay). When calculating these values, the card number, expiration date, and service code are used. All of these values are three-digit except for the CID. The CVV/CVC/CVN values are stored on the card’s track2 and are used to verify the card’s authenticity along with checking the card number, validity of its expiration date, and PIN code if available. The CVV/CVC/CVN check is performed for operations performed on the magnetic stripe and is performed by comparing the received CVV/CVC/CVN value with the newly calculated value on the issuer’s server. The values of the CVV2/CVC2 card are stored on the back of the card and are used for conducting e-commerce operations. At the time of the operation, the cardholder manually enters the card number, its validity period and the CVV2/CVC2 value. The transfer of these three parameters (card number, expiration date, and CVV2/CVC2 value) to a third party is not allowed under any circumstances, because in this case, all kinds of operations that require CVV
