Issuer Public Key Exponent

What it is

The Issuer Public Key Exponent is used together with the Issuer Public Key (recovered from certificate 90 plus remainder 92) to verify signed card data during offline data authentication. It is almost always 3 (0x03) or 65537 (0x010001).

Where it appears

Read from the card record files; used in SDAStatic Data AuthenticationOffline check where the terminal verifies a fixed issuer signature over static card data. It cannot prove the card is live, so it is vulnerable to cloning and replay.View in glossary →/DDADynamic Data AuthenticationOffline check where the card signs unique, per-transaction data with its own private key — proving the chip is genuine and not a clone.View in glossary →/CDACombined DDA / Application Cryptogram generationThe strongest offline authentication: the card signs the dynamic data and the transaction cryptogram together in one step, preventing tamper (“wedge”) attacks.View in glossary →.

Specification reference

Defined in: EMV 4.x Book 3 (Application Specification), Annex A — Data Element Dictionary

Example values

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