Generates the CVV2 (printed on the back of the card) used for card-not-present transactions. CVV2 uses the same algorithm as CVV but with a fixed service code of "000" and the expiry date in reversed format.
Inputs
PAN: Primary Account Number (card number).
Expiry Date: Card expiration date in YYMM format.
Key A: First half of the CVV key pair (8 bytes / 16 hex chars).
Key B: Second half of the CVV key pair (8 bytes / 16 hex chars).
Tips
CVV2 always uses service code "000" — the actual service code is not part of the calculation.
Same key pair is typically used for both CVV and CVV2.
CVV2 is the 3-digit code printed on the signature panel of the card.
Standards: Visa CVV2 Specification, Mastercard CVC2 Specification