P2 PIN verification: IBM 3624 and Visa PVV

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Lesson P2: What the issuer does with the PIN: natural PIN and offset, the decimalisation table, PVV.

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The opening of the lesson

Why it matters

The PIN block (module P1) gets the PIN safely to the issuer; then the issuer must decide whether it is right, without storing the PIN anywhere. Two methods dominate: the IBM 3624 offset and the Visa PIN verification value (PVV). Both run inside the issuer's HSM, and both are where a response 55 (incorrect PIN) comes from.

In the full lesson

The concept
Step by step: verifying at the issuer
In the real world
Common mistakes
What to test

What module P2 covers →

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