Anything that uses encryption to keep content away from spying eyes.
End-to-end encryption is the best, because there need be no trusted intermediary.
Links to this note
Meshtastic is a Mesh Network consisting of low-power, long-range (many miles/km), small communicators. These are little battery-powered boxes that can optionally link to a phone with Bluetooth or Wifi. The communicators form an automatic mesh and can share text messages or GPS coordinates. All traffic on meshtastic is end-to-end Encrypted.
Here are some (potentially) interesting topics you can find here:
When things are difficult – maybe there’s been a disaster, or an invasion (this page is being written in 2022 just after Russia invaded Ukraine), or maybe you’re just backpacking off the grid – there are tools that can help you keep in touch, or move your data around. This page aims to survey some of them, roughly in order from easiest to more complex.
According to the NNCP documentation, NNCP is intended to help build up small size ad-hoc friend-to-friend (F2F) statically routed darknet delay-tolerant networks for fire-and-forget secure reliable files, file requests, Internet Email and commands transmission. All packets are integrity checked, end-to-end Encrypted, explicitly authenticated by known participants public keys. Onion encryption is applied to relayed packets. Each node acts both as a client and server, can use push and poll behaviour model. Also there is multicasting area support.
NNCP lets you securely send files, or request remote execution, between systems. It uses asynchronous communication, so the source and destination need never be online simultaneously. NNCP can route requests via intermediate devices – other NNCP nodes, USB sticks, tapes, radios, phones, cloud services, whatever – leading to a network that is highly resilient and flexible. NNCP makes it much easier to communicate with devices that lack Internet connectivity, or have poor Internet.
Keeping your (digital) bits secure.