Latest Posts
-
Understanding Cryptographic Keys: The Beginner Friendly Breakdown
.
Whenever I talk to people who are new in security or payments, one thing always surprises me. The moment I say the word keys they immediately think it is something complicated or something only seniors can understand. I get that feeling because I used to be the same. When I first touched topics like symmetric…
-
What is NIST SP 800-57? A Practical Guide for Payments, Fintech, and Security Teams
.
I want to share something that honestly took me years to fully understand. If you work in fintech, in payments, or anywhere near security and compliance, you will eventually hear this one document again and again. It is called NIST SP 800 57. To be honest, the first time I saw it, it felt like…
-
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 deep. But once I actually saw how this is used in real payment flows, I…
-
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 transaction, those were the first places I had to check. If you’ve ever debugged an…
-
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 stripe. But the more I worked with terminals, kernels, and card profiles, the more I…
About Me
Hi I’m Assi—I’m dedicated to advancing cashless payment technology and sharing insights with fellow developers and solution architects on my blog, Cashless Nomad.
I embrace a mobile lifestyle by replacing cash with digital payments, enabling seamless transactions anywhere. Going cashless keeps me connected, agile, and financially flexible—perfect for traveling light and skipping currency hassles.
Checkout my other blogs at marai.dev