onionhat

Wallet apps and clients need to talk to a node somewhere to sync, broadcast, and watch addresses. Public nodes on .onion let you do that without revealing your IP to the operator. Common for Bitcoin, Zcash, Monero, Ethereum, and others. Threat model: a node sees which addresses you query and which transactions you broadcast — that linkability matters even with Tor in front, so prefer running your own when you can.