>>106030745 (OP)monopoly, as simple as.
look up what EMV means, it's basically THE standard for everything related to payment cards on the planet, it's probably the most powerful consortium in the world right now and it's owned by visa and mastercard, they basically own the entire world, china and russia included, by the balls and if they decided to they could revoke all the certificates for payment cards in a country over night, visa, discover, mastercard, it does not matter, then nobody could pay for anything.
they define the protocols, validate hardware (yes, you do you have to send them the firmware and hardware schematics and they'll decide if they authorize you to operate, forget about corporate secrets, there is no such thing for processing payment cards that follow these standards), they sign everything cryptographically and it's very hard if not impossible to bypass their processes.
if they catch you, good fucking luck, fucking with banks and related is above war crimes and genocides in term of gravity in case you didn't know, they'll just crush you.
I write firmware for various hardware, included for EMV readers, forget about your insane controlling ex, there is no one more intrusive and controlling than the EMV fuckers.
I honestly don't know what we could do about this, they're well above the laws of any country and basically untouchable even in china as unionpay decided to join the consortium a decade ago and is now submitted to the same rules as the others.
if xi decided to riot against EMV then they'll just kill unionpay over night and the entire country would go back to the stone age for some time until all the hardware is replaced, good luck doing that in a country with more than a billion people.
to communicate with EMV cards you have to connect to servers owned by companies parts of EMV, usually called payment gateway, theres is no avoiding this, that's how they would revoke certificates, forget not connecting to these servers, no server no payment