Mesh Networks
Mesh networks enable communication without centralized infrastructure — no cell towers, no ISPs, no internet required. For Bitcoiners, this is critical: payments can be agreed upon and signed offline, then broadcast when connectivity returns.
Why Mesh Matters for Bitcoin
- Blackout scenarios — traditional wallets cannot broadcast without internet; mesh enables offline coordination and Cashu ecash transfer
- Censorship resistance — no central chokepoint to surveil or shut down
- Local resilience — communicate and transact within a neighborhood or city
Technology Comparison
| Type | Radio | Range | Bandwidth | Best For |
|---|---|---|---|---|
| Wi-Fi Mesh | 2.4/5 GHz | 100 m | High | Home/City broadband backup |
| Bluetooth Mesh (BLE) | 2.4 GHz | 10–100 m | Low | Secure local chat, phone-to-phone |
| LoRa Mesh | Sub-GHz | 1–5 km | Very low | Long-range text, GPS, alerts |
| Hybrid | Multiple | Varies | Varies | Disaster response, mixed use |
Key Platforms
Bitchat (Jack Dorsey)
- Encrypted messenger using Bluetooth Low Energy (BLE)
- Noise Protocol for encryption
- Multi-hop relays through nearby devices
- Payload ~512B — sufficient for Cashu ecash tokens or signed PSBTs
- Status: Experimental; iOS focus
Meshtastic
- Open-source LoRa firmware for off-grid messaging
- Range: 1–5 km (up to 10+ km with line of sight)
- Max payload ~242B — small but usable for Cashu tokens
- Supports GPS sharing, encryption, and store-and-forward
- Hardware: TTGO LORA32, Heltec, RAK Wireless
- Best for: Neighborhood-scale, camping, disaster prep
Briar
- Decentralized Android messenger
- Bramble protocol for privacy and metadata resistance
- Store-and-forward via trusted contacts
- Works over Tor, Wi-Fi, or Bluetooth
- Limitation: Android-only;
Bitcoin + Mesh Workflow
- Online phase — mint Cashu tokens or create a presigned PSBT
- Offline phase — copy token/PSBT to clipboard
- Transfer — send via Bitchat BLE, Meshtastic, or Briar while disconnected
- Relay — message hops device-to-device until it reaches the recipient
- Online phase — recipient redeems Cashu or broadcasts the PSBT
Limitations
- Trust in mint — Cashu requires an online mint to redeem; mesh only covers the transfer layer
- BLE hop scalability — crowds may saturate Bluetooth mesh capacity
- Power — mesh devices need charging; LoRa is low-power but not zero
- Range vs density — LoRa needs fewer hops but lower bandwidth; BLE is dense but short-range
Future
- Mesh-first Bitcoin wallets that natively create and transfer PSBTs or ecash
- Community-run Cashu mints with mesh-aware payout endpoints
- Hybrid networks combining BLE (dense) + LoRa (long-range) + Wi-Fi (backhaul)