EMV Payments
-
EMV Cryptograms Explained: ARQC, TC, and AAC Made Simple
.
I want to talk to you about something that confused me a lot back when I first started working with EMV transactions. If you are like me, when you hear the word cryptogram, it feels like something advanced or very…
-
TVR, TSI and IAC: The Brains Behind EMV Logic
.
When I first started working on EMV transaction processing, I remember feeling completely lost looking at those cryptic acronyms such as TVR, TSI and IAC. They looked like random three-letter codes, but every time something went wrong in an EMV…
-
How EMV Makes Decisions: Processing Restrictions & Terminal Action
.
I’ve spent a good part of my career dealing with EMV transactions. When I first got into this space, I thought EMV was just about encrypting card data and making sure the chip was harder to copy than a magnetic…
-
Cardholder Verification Explained: PIN, Signature, and More
.
When I first started working on EMV transactions, one of the things that confused me the most was cardholder verification. I was so focused on getting the terminal to talk properly to the card, sending the right APDUs, and parsing…
-
Reading EMV Records: How Terminals Get What They Need
.
I want to share something with you today that brought me a lot of headaches when I was working on my first contactless EMV implementation. If you’re diving into EMV transactions, especially building or testing somethink like a SoftPOS or…
-
What Happens When You Tap or Insert? A Look at GPO and AFL
.
When I first started working with EMV transactions, I used to wonder: what really happens the moment you tap or insert your card? On the surface it looks so simple, the card is near the terminal, something blinks, and then…
-
How Terminals Select the Right Application on an EMV Card
.
When I was building an EMV payment terminal for one of our retail clients a few years ago, one of the things I had to understand deeply was how the terminal figure out what application to use when a card…
-
Best Tools to Analyze EMV Cards Like a Pro
.
When I started working on EMV projects, I thought reading data from a chip card was just about plugging it into a reader and magically the data will appear on my screen. I was wrong. The reality is that EMV…
-
Top 25 EMV Tags You Should Know (and What They Mean)
.
Back when I was integrating a POS system for a merchant in the Philippines, one of our biggest headaches was interpreting EMV data, especially when certification time came. At first, all these TLVs looked like encrypted gibberish. But over time,…
-
Offline vs Online EMV Transactions: What’s the Difference?
.
When I was working on an EMV terminal integration project for a merchant acquiring platform, one of the most confusing things for me at first was this: why do some EMV card transactions go through even if the terminal is…