This glossary is included upfront to help you understand the acronyms and their descriptions. These acronyms are commonly used throughout this guide.

Acronym Description
AAC Application Authentication Cryptogram – the type of AC that is generated by the chip when declining a transaction.
AC Application Cryptogram – cryptogram returned by the ICC in response of the Generate AC command.
AID Application Identifier – identifies the application as described in ISO/IEC 7816-5. A unique identifier that can tell you the brand of card (ex: Amex, Discover, MasterCard, Visa, etc.) and the type of card within the brand (ex: Maestro vs. MasterCard Credit).
ARPC Application Response Cryptogram – cryptogram generated by the issuer during an online transaction authorization. It secures the response data integrity and is used by the chip to validate the issuer host authenticity.
ARQC Application Request Cryptogram – a type of AC requesting an online transaction. It secures the request transaction data integrity and is used by the issuer to validate the chip authenticity.
BAU Business as Usual – in this document, often used to refer to normal magstripe processing flow.
CVM Cardholder Verification Method – strongest verification method supported by both the ICC chip and the EMV Kernel’s terminal capabilities configuration.
TC Transaction Cryptogram – approval cryptogram generated by the ICC.
TPP Third Party Processor – the merchant’s acquirer. The Elavon Fusebox gateway solution is certified to multiple TPP endpoints.
TVR Terminal Verification Results – status of the different terminal risk management and cardholder verification functions as seen from the terminal.