There's Long Key, which is pretty good.
I otherwise am of the firm belief that so long as a machine is connected to the Internet, or we can hear the keyclicks nearby, that it's total folly to believe any data is safe, many air gaps included. There's a variant of Murphy's Law stated thusly: with a big enough hammer, you can break anything.
Perhaps your router was slipstreamed some code enroute to the data center. Maybe it was your little RAID 6 array. Perhaps the kernel has had a long dormant back door or nice stack overflow to hijack. Ever plugged in your smartphone to your machine to maybe, synch something?
My guess is that in one way or another, we're all already infected, it's just a matter of hassle to get what's needed by those desiring to smash you. You may believe this to be dystopian, but once you take a long look at the CVEs out there, multiply them by two for the probably-unknowns, and even machines living their life solely in Faraday cages become suspect.