Nomad, communicate off-grid mesh, forward secrecy and extreme privacy

Original Article ↗ Hacker News Discussion ↗

An experimental messaging system called NomadNet, built on the Reticulum mesh networking stack, aims to enable off‑grid, privacy‑preserving communication over diverse transports such as LoRa, HF radio, Wi‑Fi and even sneakernet. Commenters are intrigued by Reticulum’s coordination‑less routing, ultra‑low bandwidth requirements and ecosystem (e.g., mobile clients, microcontroller ports), but raise hard questions about flood resistance, Sybil attacks, formal threat modeling, and the lack of a security audit. Related themes include legal constraints on encrypted radio use, practical deployment challenges on iOS and legacy hardware, and how Reticulum compares to systems like Yggdrasil, IPFS, Briar, Meshtastic and Tor.

Reticulum & NomadNet Capabilities

  • Built on the Reticulum network stack, which can run over many media (LoRa, BLE, packet radio, Tor/I2P, HF, etc.) as long as bandwidth > ~5 bits/s and MTU ~500 bytes.
  • Demonstrated over HF radio with ~90-mile separation, bridging an HF node to a TCP-based testnet so off-grid nodes can reach wider peers.
  • Ecosystem includes desktop (NomadNet), mobile (Sideband), browser client (MeshChat), and microcontroller firmware.

Routing, Announces, and Flooding

  • Reticulum uses “announces” that are flooded only for routing information. Nodes store next-hop info; data packets then follow a single path using hop-count.
  • To mitigate flooding, only a small fraction (~2%) of channel bandwidth is used for announces, with priority for lower-hop ones, which biases routes toward faster paths in practice.
  • Skeptics question resilience against Sybil-style attacks (e.g., generating vast numbers of fake addresses/announces). Mitigations mentioned: announce caps and rate-limiting per interface, but comprehensive source-flood protection and a formal threat model are described as unclear.

Blockchains, Sybil Resistance, and Alternatives

  • Explicitly no blockchain is used. Some argue that mesh + blockchain are ill-matched (consistency vs partition tolerance).
  • Long side-thread debates whether blockchains or other consensus schemes are necessary or useful for Sybil resistance; views range from “all blockchain is useless” to “various non-blockchain distributed approaches can work.”

Transports, Radio, and Legality

  • Reticulum can be used over ham bands, but US rules generally prohibit encryption on amateur radio; ISM bands (e.g., LoRa, WiFi) avoid this issue.
  • Discussion of HF legality, CB restrictions (voice-only, no digital), and FCC’s slow reconsideration of “no encryption” rules.
  • Concern over potential loss of 900 MHz ISM spectrum to commercial interests.

Hardware, Performance, and Sneakernet

  • Python implementation seen as heavy for very old hardware, but there is a C++ microReticulum for ESP32 and RNode firmware for LoRa boards.
  • Supports very low bandwidth and even “sneakernet” via printed QR messages that can be scanned and injected into the mesh.

Security, Auditing, and Usability

  • Software is beta and not externally audited; some see that as acceptable for non-commercial projects, others worry about privacy-breaking bugs.
  • No clearly documented, formal threat model yet; interested readers are pointed to the manual and community forums.
  • Usability critiques: long hex identities are hard to handle; suggestions include decimal/base32 and better grouping. Users must understand what “trust” levels mean.
  • Concerns that true privacy also requires trusted input devices and minimal, auditable software stacks, not typical mobile OS keyboards.