“Airgap” refers to a computer (or network) that is physically disconnected from a larger network and the Internet.
This word originated in the pre-wifi days, when there was literally air between machines; that is, no connecting communication cables. Nowadays, it also refers to a lack of radio (wifi or otherwise) communication. That is, it is complete physical isolation.
Airgapped systems are often desirable in situations where Computer Security is important. For instance:
- Handling sensitive or classified information
- Backups and archiving
Tools for Communicating Offline and in Difficult Circumstances can facilitate airgapping. NNCP in particular can be useful.
The page Dead USB Drives Are Fine: Building a Reliable Sneakernet talks about using NNCP to build a reliable airgapped network.
My page How gapped is your air? discusses the potential shortcomings of airgapped systems and alternatives that exist.
Links to this note
Sometimes we want better-than-firewall security for things. For instance:
I loaded up this title with buzzwords. The basic idea is that IM systems shouldn’t have to only use the Internet. Why not let them be carried across LoRa radios, USB sticks, local Wifi networks, and yes, the Internet? I’ll first discuss how, and then why.
“OK,” you’re probably thinking. “John, you talk a lot about things like Gopher and personal radios, and now you want to talk about building a reliable network out of… USB drives?”
Keeping your data safe in the event of a disaster or compromise is important. That’s why we back up.
Keeping your (digital) bits secure.
I sometimes see people read about NNCP and wonder “This sounds great! But… what can I do with it?” This page aims to answer those questions.
Here is a comparison of various data backup and archiving tools. For background, see my blog post in which I discuss the difference between backup and archiving. In a nutshell, backups are designed to recover from a disaster that you can fairly rapidly detect. Archives are designed to survive for many years, protecting against disaster not only impacting the original equipment but also the original person that created them. That blog post goes into a lot of detail on what makes a good backup or archiving tool.