Reticulum — a radio protocol for mesh network. Encrypted peer-to-peer communication without the Internet.

[Man]

As we discussed earlier, shutting down the Internet in a specific country or city is not an imaginary threat, but a completely feasible action. In particular, the international association Internet Society recorded 49 artificially caused shutdowns in 2021.

But there are effective technologies that will allow you to survive a possible shutdown. For example, mesh networks for radio communications.
One of the latest developments in this area is the Reticulum Network Stack (RNS).

Many fragmentary solutions and specialized tools have been created by now, but until now there was no complete communication stack for a mesh network that can be set up by ordinary users without any centralized coordination. The developer of RNS tried to fill this gap.

Such a network can be deployed in half an hour in the event of a systemic communication failure in a specific area or worldwide. No drivers or kernel modules for embedded OS are required. The network stack can be easily installed on any radio modem, and this operation does not require special experience with computers or radio transmitters (full documentation, pdf).

RNS operates on a completely new protocol that has a number of advantages over the IP protocol (although IP is also supported).

The main advantages of Reticulum over traditional network stacks are support for very low bit rates and very high delays. That is, you can transmit packets over the simplest radio channels during short-term communication sessions. At the same time, end-to-end encryption and complete anonymity are maintained.

Stack Features​

• Coordinate-free global addressing and identification.
• Fully self-configuring multi-hop routing.
• Asymmetric encryption X25519 and signatures Ed25519.
• Fernet Encryption Specification:
  • AES-128 in CBC mode with PKCS7 padding;
  • HMAC with SHA256 authentication;
  • generating initialization vectors using os.urandom();
  • Forward Secrecy with Ephemeral Keys over Elliptic Curve Diffie–Hellman (ECDH), set Curve25519.
• Tamper-proof package delivery confirmations.
• Variety of interface types.
• Intuitive and easy to use API.
• Reliable and efficient transmission of arbitrary volumes of data.
  • support for multi-gigabyte files;
  • automatic calculation of checksums, coordination and restoration of packet sequence;
  • extensible request/response mechanism.
• Effective connection establishment: three packets with a total size of 237 bytes, then the connection maintenance cost is 0.62 bits per second.

The developer of the network stack is Mark Quist , an experienced developer and network engineer who has spent his entire life creating and managing computer networks. He is the owner of Unsigned.io, a company that develops and sells radio communication equipment (RNode modules, MicroModem and OpenModem modems).

Reticulum can run on almost any device, starting with a tiny Raspberry Pi Zero. According to Quist, with Reticulum, people with minimal knowledge of telecommunications and computers can set up a long-range messaging system for their community.

For example, you can easily set up a mesh network within a city and establish a VHF communication channel with a neighboring city, says Quist: “If you already have a modem and a radio transmitter, it takes five minutes to set up. I really tried to make the stack as flexible as possible, but at the same time very easy to use for people with minimal experience with computers and radio transmitters.”

How this looks in practice can be seen in the example of Nomad Network. This is a prototype of a sustainable mesh network based on the LXMF and Reticulum protocols.

Devices in the Nomad Network

This project is fundamentally different from many other mesh network projects in the world, such as the public city network NYC Mesh. All of them aim to eventually connect to the Internet. But here, a network separate from the Internet is created from the start, and with strong encryption. This is a fundamentally different level. In fact, Reticulum supports a full-blown apocalypse scenario.

“Reticulum is an attempt to create an alternative base-layer protocol for data networks,” says the author. “In essence, it is not a single network, but a tool for building networks. It can be compared to IP, the Internet Protocol stack that the Internet and 99.99% of all other networks on Earth operate on. It solves the same problems that the IP stack does, providing digital data transfer from point A to point B, but it does it in a completely different way and with completely different assumptions. The real power of the protocol is that it can use all sorts of different communication media and connect them together into a single network. It can use [long-distance] transceivers, modems, radios, Ethernet, WiFi, or even a roll of old copper wire if you have that kind of capability."

Encrypted messaging on the Nomad Network

A few more screenshots

Reticulum development is still in its infancy. The program code has not been audited for encryption security. That is, in reality, it is too early to use it in a serious matter.

Another problem is that all existing network software is written for the IP protocol. Therefore, a new software stack will have to be created for the Reticulum network stack: existing programs will not work there. Although some things have already been developed. For example, the Sideband messenger (Android, Linux, MacOS) for exchanging text messages via LoRa, packet radio, WiFi, I2P or any other transport protocol supported by the LXMF peer-to-peer communications stack.

Source