[Cryptography] samizdat phone-to-phone ad-hoc anti-censorship

[John Denker]

Hi --

Short version: What's the best way to set up a completely
ad-hoc from-scratch communication network?

Once upon a time, there was a country with strict censorship.
Office photocopy machines were strictly regulated, because
they could be used for samizdat i.e. surreptitious copying
followed by hand-to-hand distribution.

Now suppose hypothetically there was some present-day locale
with martial law and super-strict censorship. Suppose the
usual messaging apps and social media sites were shut down.
Maybe all the network infrastructure down. One could imagine
countering this by propagating information from phone to
phone, via bluetooth, near-field, or whatever.

The result would be an ad-hoc samizdat network. It would
take days (not milliseconds) to propagate news around the
world, but that's better than no news at all. It would not
be an IP network; we are not trying to re-invent RFC 1149
IP over Avian Carriers.
   https://datatracker.ietf.org/doc/html/rfc1149

Bluetooth file transfer is a known thing, implemented on
Android OS, Fire OS, Windows OS, Mac OS, and Linux OS.
   https://www.lifewire.com/bluetooth-file-transfer-4147725

— Is there an app that makes this easier?
— Would it be better to do it without an app, for maximum
deniability?

What is the next move in the cat-and-mouse game? What if
the authorities criminalize the file-transfer feature?
Or criminalize bluetooth altogether?

I assume it would make sense to use an old device with no
sim card and/or in airplane mode, to make it harder to
track the device. What are the best practices?

Asking for a friend....