: You start with a Master Derivative Key (MDK) and "diversify" it using the card’s PAN to get a Unique Derivation Key (UDK).
| Practice | Reason | |----------|--------| | | Real issuer master keys (IMKs) would be a catastrophic leak. | | Run on air-gapped machines | Prevent network exfiltration of generated cryptograms. | | Log all executions | Audit trail for who generated which ARQC, when. | | Never process production PANs | Even test ARQCs with real PANs could be used in phishing. | | Wipe memory after use | Session keys persist only during execution; ensure no core dumps. | arqc-gen.exe
If you are looking at a packet capture (like Wireshark) of an EMV transaction, you must extract the correct tags to feed into the tool. The standard input for ARQC generation usually concatenates the following tags in order: : You start with a Master Derivative Key
Thus, arqc-gen.exe is a software implementation of the cryptographic algorithms normally executed inside a physical smart card’s secure chip. | | Log all executions | Audit trail