ZKA (German Banking Standard)

• SK Derivation tab: Enter Master Key (MK), Command Data (CM), and Random Number (Rnd) in hexadecimal format (32 hex characters each). Click "Derive SK" to generate the session key.

• PIN tab: Enter the session key (SK-pac) and PIN block (8 bytes, 16 hex characters). Click "Encrypt" to encrypt the PIN block or "Decrypt" to decrypt it.

• MAC tab: Enter the MAC key (32 hex characters) and data in hexadecimal format. Click "Calculate MAC" to generate the message authentication code.

• All inputs must be in hexadecimal format. Keys are 16 bytes (32 hex characters), and PIN blocks are 8 bytes (16 hex characters).