@hj @proxeus with a few exceptions, anything with a smart chip is running embedded Java. The computer contains one or more embedded Java applets which provide functionality like holding a private key and doing challenge-response authentication. I have a smart card for using the laundry machines in my apartment complex.

Embedded Java is a very reduced version of Java though.

Here's a Java ring with an embedded smart chip from 1998  https://shitposter.club/attachment/2460755

  I believe the Yubikey OpenPGP functionality is a Java applet.