I'm not saying that writing for Javacards is easy, but that's not the problem here. There is plenty of software written already https://github.com/EnigmaBridge

I'm not saying that writing for Javacards is easy, but that's not the problem here. There is plenty of software written already https://github.com/EnigmaBridge/javacard-curated-list https://github.com/EnigmaBridge/javacard-curated-list It's just didn't catch on, there's no thriving community around it. You have the software, you have the hardware (search for JCOP21 or JCOP3 on Aliexpress), but no users.