Verify Dynamic CVV

Command:

Verify a Dynamic CVV.

Notes:

The PAN sequence number is assumed to be zero for the calculation of the UDK. This command will append a zero to the supplied PAN when generating the *DK-AC.

The EMV “Track 2 Equivalent Data”, provided in the authorisation message and originating from the contactless smart card, is the source for the following data fields for the PW command:

·  PAN

·      Expiration Date

·       Service Code

·       ATC

·  DCVV

To assist in development of host applications, the calculated Dynamic CVV will be provided in the response data if Error Code 01 is returned and the HSM is in Authorised State.

Field

Length & Type

Details

COMMAND MESSAGE

Message header

m A

(Subsequently returned to the Host unchanged).

Command code

2 A

Value PN.

Scheme ID

1N

Identifier for Card Scheme

0 = Visa

1 = MasterCard PayPass

Other values RFU. 

Version

1N

For Scheme ID = 0:

0 = Visa dCVV

For Scheme ID = 1:

0 = MasterCard PayPass.

Other values RFU. 

*MK-DCVV

32H or 1A + 32H

Master Key from which card-unique key is derived.

For scheme ID = 0 this will be a *MK-AC encrypted under LMK 28-29 variant 1

For Scheme ID = 1 this will be a *MK-CVC3 encrypted under LMK 28-29 variant 7

Key Derivation Method

1A

Method to be used to derive a card-unique key from the Master Key

‘A’ = EMV4.1 Book 2 Option A method (Ref 6 section A1.4.1)

‘B’ = EMV 4.1 Book 2 Option B Method (Ref 6 section A1.4.2)

PAN

nN

The Primary Account Number for the card

Delimiter

1A

Value “;”

Identifies the end of the PAN field

For Scheme 0 (Visa dCVV) the following 4 fields are present

1) Expiration Date

4N

The Card Expiry Date

2) Service Code

3N

The Card’s Track 2 Service `Code

3) ATC

6N

Application Transaction Counter.

If the ATC provided on Track 2 is less than 6 digits, it should be right justified and padded on the left with zeros.

4) dCVV

3N

Dynamic CVV to be validated.

For Scheme 1 (MasterCard Paypass) the following 4 fields are present

1) IVCVC3

5N

The issuer proprietary static data element.

Max value 65535 (2 byte field)

2) Unpredictable Number

10N

Decimal value of random number provided to the card by the terminal during a PayPass transaction

Max value 4294967295 (4 byte field)

3) ATC

5N

Decimal value of Application Transaction Counter.

Max value 65535 (2 byte field)

4) CVC3

5N

Dynamic CVV to be validated.

Max value 65535 (2 byte field)

End message delimiter

1 C

Optional. Must be present if a message trailer is present. Value X’19.

Message trailer

n A

Optional. Maximum length 32 characters.

 RESPONSE MESSAGE

Message header

m A

Returned to the Host unchanged.

Response code

2 A

Value PN.

Error code

2 N

00 : No errors

01 : dCVV verification failed

05 : Unrecognised Scheme or Version ID

10 : *MK-AC Parity Error

67 : Command not licenced

Diagnostic Data

3N (Scheme 0)

or

5N (Scheme 1)

The calculated dCVV

Only present if Error Code 01 is returned and the HSM is in Authorised State.

End message delimiter

1 C

Present only if present in the command message. Value X’19.

Message trailer

n A

Present only if present in the command message. Maximum length 32 characters.