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Torn Transactions

Torn is an EMV feature specified by some payment networks in the context of contactless card processing.

Mastercard

JCB

CUP

PURE

Rupay

Agnos Availability

Supported

Supported

Not Supported

Supported

Not Supported

Configuration

  • 0xDF811D, torn depth

  • 0xDF811C, max lifetime

  • 0xDF1D, torn depth

  • 0xDF1C, max lifetime

  • 0xDF1D, torn depth

  • 0xDF1C, max lifetime

  • C7 B3b6, Terminal Transaction Processing Information

Trigger

  • Generate AC not completed

  • Generate AC not completed

  • Read Record not completed

  • Generate AC #1 and Generate AC #2 not completed

Restart

  • Start B

  • END APPLICATION

  • Start B

  • PRESENT CARD AGAIN

  • TRY AGAIN

  • Start B

  • PRESENT CARD AGAIN

  • TRY AGAIN

  • Start B

  • PRESENT CARD AGAIN

Storage Mechanism

  • When a torn occurs, add a torn record:

    • 57 (primary key)

    • if CDA supported:

      • 9F38

      • 8C

      • 9F37

  • When a torn occurs, add a torn record:

    • 9A (primary key)

    • 9F21 (primary key)

    • PAN for 5A and/or 57 (primary key)

    • 57

    • 94

    • 9F36

    • 82

    • 9F10

    • 9FD

    • 9F6C

    • 9F37

    • 9F26

    • 9F02

    • 5F2A

Check Point

  • The kernel is reactivated to perform a brand new transaction

  • After Final Select, the kernel checks whether there is a torn situation

  • Indicator: AgnosTVR B20b1

  • The kernel is reactivated to perform a brand new transaction

  • Before Final Select, the kernel checks whether there is a torn situation

  • The kernel is reactivated and is set to jump to one of the torn states (when the torn was detected):

    • Recovery from Generate AC #1

    • Recovery from Generate AC #2

Too Old Verification

  • Yes

  • No

  • Yes. If too old then torn record is removed

  • No

Recovery Mechanism

  • Echo performed at a specific state, occurring between Final Select and GPO

  • Tearing Transaction Recovery

  • Echo performed right after the occurrence of the Generate AC (once the start B was processed by the entry point)

Recovery APDU

  • 80 DF 00 00 00

  • Not implemented

  • 80 DF 00 xx where xx corresponds to the Generate AC number (1 or 2)

Recovery Principle

  • From Echo command, fetch tags to be used at Generate AC time

  • Not implemented

After Recovery

  • Card processing is resumed to reach the next step: GPO

  • Not implemented

When recovery fails

  • If communication error:

    • END APPLICATION

    • Start B

    • A brand new transaction will start

  • Else

    • The transaction is resumed:

      • In torn mode if no status word error

      • Like a regular transaction is any other error

N/A

  • Generate AC #1 recovery:

    • If communication error:

      • TRY AGAIN

      • Start B

      • A brand new transaction will start

    • Else if cancellation:

      • END APPLICATION

      • STOP

    • Else if status word error:

      • SELECT NEXT RETRY

      • Start C

      • A brand new transaction will start

    • Else (normal path):

  • Generate AC #2 recovery:

    • if communication error:

      • TRY AGAIN

      • Start A

      • A brand new transaction will start

    • Else (normal path)

      • Attempt to perform EMV completion

Specifics

N/A

  • The ability to support a torn transaction also depends on the card (presence of PURE Echo card id, tag 9F75, in FCI/BF0C)

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