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Capk

Aug 17, 20266 min read

Debugging EMV Offline Data Authentication: DDA, CDA, DDOL and CAPKs

When Offline Data Authentication (ODA) fails, replacing Certification Authority Public Keys (CAPKs) at random is rarely productive. Most field failures sit earlier in the chain: …

Apr 09, 202615 min read

CAPKs: The Cryptographic Trust Anchors Behind Every EMV Transaction

Every card-present transaction begins with a question the terminal must answer before anything else: is this card genuine?