Translates (re-encrypts) a PIN block from one Zone PIN Key (ZPK) to another. Used when PIN blocks traverse network boundaries — each network leg uses a different ZPK, so the PIN block must be translated at each switch.
Inputs
PIN Block: The encrypted PIN block in hexadecimal (16 hex chars).
Source ZPK: The current Zone PIN Key that the PIN block is encrypted under (16 bytes / 32 hex chars).
Destination ZPK: The new Zone PIN Key to re-encrypt the PIN block under (16 bytes / 32 hex chars).
Tips
PIN translation is a core HSM function performed at every network switch in the payment chain.
The PIN is never exposed in clear — it is decrypted and re-encrypted inside the HSM.
Source and destination ZPKs are typically exchanged as TR-31 key blocks.