Specifies the current keys that are in use in the PIN pad and by Paymentech.
The EncryptedKeyIndex specifies the current keys that are in use on the host (Paymentech) and in the PIN pad. This EncryptedKeyIndex is updated after every transaction, and is required to be sent in all transactions except a RequestCurrentKeys transaction. The normal range is from 1 through 9. The default is zero (0), and indicates that no encryption keys have been established. Transaction requests should never be sent with a value of zero (0). Note that MACReversals must be sent with the EncryptedKeyIndex from the original transaction to insure that the EncryptedPIN can be properly translated by the host.
Keys are required to be renewed every:
- 200 Transactions
- 24 Hours
- Each time a Batch is released for settlement
- Whenever the PIN pad loses sync with the server