There is another backchannel that can be used if your air-gapped computer ever does get compromised, which I haven't seen anyone discuss yet. If your internet-

There is another backchannel that can be used if your air-gapped computer ever does get compromised, which I haven't seen anyone discuss yet. If your internet-connected computer and air-gapped computer both have audio speakers / microphone, then that seems like a perfect covert way for a compromise to set up wireless communications between them An audio signal can appear to be similar to fan noise, or outside of human hearing range. I wonder if this has ever been exploited before.