Communicating with an air-gapped system

Posted Oct 5, 2017 13:17 UTC (Thu) by genaro (subscriber, #82632)
In reply to: Communicating with an air-gapped system by drag
Parent article: Strategies for offline PGP key storage

> If you want something really dumb and simple and one-way then printing out to QR code and getting brain-dead 2d code scanner may be useful. The simple scanners are essentially just keyboards that type out whatever you scan in + a programmable code ( tab key vs return key, etc).

I did a research paper in college on this topic. It's feasible to export ascii-armored keys and read them with QR. 4096-bit RSA keys are rough, but workable. With newer EC keys the QR method gets much, much easier.