get
Retrieves the current Key Serial Number (KSN) for a DUKPT key. If the required key does not exists it must not throw a exception, instead it must return an empty Byte Array
The KSN uniquely identifies the transaction state for DUKPT keys, allowing tracking and verification of key usage.
Return
The current KSN value as a byte array (10 bytes) or an empty Byte Array.
Parameters
e
The DUKPT key purpose (CryptoKeyPurpose).
i
The index of the DUKPT key (0–99).