PIN Block Calculator

PIN blocks are formatted representations of a PIN that protect the PIN during processing. The ISO 9564 standard defines several PIN block formats, with Format 0 and Format 1 being the most common in payment card processing.

ISO 9564 Format 0 (ANSI X9.8):

Format 0 combines the PIN with a transaction-specific value derived from the PAN (Primary Account Number). This format is widely used in ATM and POS transactions.

• PIN is padded with random digits to create a 16-digit value
• First digit indicates the PIN length (e.g., '4' for a 4-digit PIN)
• XORed with the rightmost 12 digits of the PAN, padded with zeros

ISO 9564 Format 1:

Format 1 is similar to Format 0 but uses a different padding method. It's commonly used in older systems.

• PIN is padded with hexadecimal 'F' digits
• First digit indicates the PIN length
• XORed with the PAN in the same way as Format 0

PIN Block Security:

• PIN blocks are typically encrypted using DES or 3DES before transmission
• The combination of PIN block formatting and encryption provides two layers of security
• Using the PAN in the PIN block creation ensures that a compromised encrypted PIN block cannot be used with a different card
• PIN blocks are never stored, only created for transaction processing