Also in that article, I discuss tools like
#dar,
#kermit,
#gensio, and
#NNCP that can help you carry data to or from sensitive systems without using a traditional network. Also I mention data diodes (
#datadiodes) - hardware devices that let data flow in only one direction. Interesting ideas there.
https://changelog.complete.org/archives/10571-how-gapped-is-your-air