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PIN Offset (IBM 3624)

Calculate offsets and recover PINs using the IBM 3624 method.

8/16/24 bytes: DES or two-key/three-key TDES.

4-12 digits. Offset length must equal the original PIN length.

Maps HEX digits 0-F to decimal digits 0-9.

16 HEX characters. If blank: rightmost 12 PAN digits excluding the check digit, followed by FFFF. This is this tool’s default convention; issuer layouts vary. Explicit data overrides PAN.

Calculator reference

Verification evidence and limitations →

What it calculates

Calculates full-length IBM 3624 offsets or recovers PINs using an offset.

Inputs and methods

DES/TDES PVK, 4-12 PIN or offset digits, 16-digit decimalization table, and eight-byte validation data.

Worked example

Key 0123456789ABCDEFFEDCBA9876543210; PAN 4111111111111111; PIN 1234; default table and validation convention.

Offset: 3104; recovered PIN: 1234

Specification and limits

Blank validation uses the rightmost 12 PAN digits before the check digit plus FFFF. Issuer layouts vary. Check length equals PIN length; no truncated-offset recovery.

IBM PIN offset generation ↗