Published on: 2015-05-27T10:16:49+00:00
During a conversation on the Bitcoin-development mailing list, Matt Whitlock shared his experience of operating a Bitcoin-only Wi-Fi network at the Porcupine Freedom Festival ("PorcFest") in New Hampshire. He poisoned the DNS and rejected all outbound connection attempts on port 8333, forcing all the wallets to connect to a single local full node, which had connectivity to a single remote node over the internet. This allowed all the lightweight wallets at the festival to have Bitcoin network connectivity while only needing to backhaul the Bitcoin network's transaction traffic once. The backhaul was a 3G cellular internet connection, and the local Bitcoin node and network router were hosted on a Raspberry Pi with some Netfilter tricks to restrict connectivity.Whitlock also mentioned that in the future, bitcoinj is likely to bootstrap from Cartographer nodes (signed HTTP) rather than DNS, and they're working towards Tor by default. Therefore, the approach used at PorcFest may not work in the future, and there might be a need for a ZeroConf/Rendezvous solution to capture Bitcoin traffic away from Tor.The discussion also touched upon the importance of preventing Sybil attacks. Kevin Greene advised choosing a diverse and unpredictable set of peers to make it difficult for attackers to carry out such attacks. However, he also recommended having a few local nodes to improve propagation while maintaining diversity in the peer set.Furthermore, the conversation explored the possibility of lightweight devices finding a full node on the same LAN to peer with instead of using WAN bandwidth. Jim Phillips suggested using a zero-conf service discovery protocol for this purpose. He envisioned a future where lightweight devices within a home use SPV over WiFi to connect with a home server, which relays transactions to larger and faster relays on the Internet. This approach could result in lower traffic across slow WAN connections, especially when there are numerous small SPV devices monitoring the blockchain in a single home. However, Phillips acknowledged that a significant number of devices would be required before the total bandwidth exceeds downloading a full copy of the blockchain. Nonetheless, hosting one's own full node is seen as more trustworthy.In summary, Matt Whitlock shared his experience of operating a Bitcoin-only Wi-Fi network at PorcFest, Kevin Greene emphasized the importance of diversity in preventing Sybil attacks, and Jim Phillips discussed the potential use of a zero-conf service discovery protocol for lightweight devices to connect with a full node on the same LAN.
Updated on: 2023-08-01T12:49:14.273723+00:00