Running Bitcoin Over Tor — Network-Level Privacy Guide

Bitcoin Over Tor

Most Bitcoin privacy discussions focus on the blockchain. But there's an equally important layer: the network layer. When you broadcast a transaction, your IP address can be correlated with that transaction. Tor fixes this.

Why Network Privacy Matters

When you broadcast a Bitcoin transaction from your node, the first node to relay it is likely yours. Network observers (ISPs, governments, surveillance companies) can correlate:

• Your IP address with specific transactions
• Your IP with your node (and thus your wallet)
• Your transaction timing with your physical location

In Sri Lanka, where ISPs are limited and government surveillance capabilities are growing, network privacy is particularly relevant.

Setting Up Bitcoin Core Over Tor

Method 1: Tor-Only Mode

Configure Bitcoin Core to only connect through Tor:

proxy=127.0.0.1:9050
listen=1
bind=127.0.0.1
onlynet=onion

This creates a Tor hidden service for your node. Other nodes connect to you via your .onion address.

Method 2: Hybrid Mode

Connect to both clearnet and Tor peers. This improves connectivity while still offering some privacy. Your outgoing connections go through Tor, but you also accept clearnet connections.

Which Mode?

• Tor-only: Maximum privacy but slower and fewer peers
• Hybrid: Better performance, still hides your transaction broadcasts
• If you use Umbrel or Start9, Tor is configured by default

Lightning Over Tor

Lightning nodes can also run as Tor hidden services. This hides your node's IP while still participating in the network.

LND Configuration

LND supports Tor natively. Key settings:

• tor.active=true
• tor.v3=true
• tor.streamisolation=true (uses different Tor circuits for different peers)

Trade-offs for Lightning

• Latency: Tor adds 1-3 seconds of latency. For Lightning payments (which need multiple round-trips), this is noticeable
• Reliability: Tor circuits can be unstable, leading to disconnected channels
• Routing: Tor-only nodes may be less preferred by routing algorithms due to higher latency

Beyond Tor: Alternative Privacy Networks

• I2P: Bitcoin Core supports I2P since v22.0. Less popular than Tor but growing
• CJDNS: Encrypted IPv6 mesh networking, supported in Bitcoin Core
• Dandelion++: Transaction relay protocol that obscures the origin. Part of Bitcoin Core's relay strategy

VPN vs Tor for Bitcoin

A VPN hides your IP from peers but the VPN provider sees everything. Tor routes through multiple relays — no single entity sees both your IP and your traffic. For Bitcoin, Tor is strictly superior to VPNs for privacy (though a VPN can complement Tor for ISP-level censorship bypass).

Practical Setup for Sri Lanka

Sri Lankan ISPs don't typically block Tor, but speeds can be slow. My recommendation:

1. Use Umbrel (Tor by default) for your Bitcoin + Lightning node
2. Connect your mobile wallets through Tor when possible (Phoenix supports Tor)
3. For exchanges, use Tor Browser or a VPN

Network privacy is the missing piece of Bitcoin privacy. You can CoinJoin all you want, but if your ISP knows you're running a Bitcoin node and can correlate your transaction times, your on-chain privacy is weakened.

Node setup guides including Tor at our learning center.