EMV

EMV (Europay, Mastercard, Visa) secures card-present transactions with chip-generated cryptograms. The terminal sends ARQC to the issuer; issuer validates and returns ARPC. EMV reduces counterfeit fraud vs magnetic stripe.

// EMV Transaction Flow
// 1. Card + terminal perform mutual authentication
// 2. Card generates ARQC (Authorization Request Cryptogram)
// 3. Terminal sends ARQC in DE55 (ICC data) via ISO 8583
// 4. Issuer HSM validates ARQC, returns ARPC

// DE55 ICC Data (TLV encoded)
9F26 Application Cryptogram (ARQC)
9F36 Application Transaction Counter
95   Terminal Verification Results
9F37 Unpredictable Number

// Issuer HSM validation (conceptual)
HsmResult result = hsm.verifyArqc(
    pan, atc, arqc, amount, currency, terminalCountry);