I like the idea of a hardware set up for this. One thing I'm considering for DiskerNet (dn - an offline, searchable, curated archive of the web that works in a normal browser) is using NNCP for updates. That way you can "request" pages that aren't in the archive, and "patch" them in from hardware updates later, USB sticks, floppies (haha) - whatever! And securely, thanks to the crypto in NNCP.

If anyone has a better idea of a protocol for this than NNCP, please suggest at: https://github.com/DO-SAY-GO/dn/issues/221