Bitcoin Audible
Chat_173 - The Time Has Come for Privacy on Bitcoin with Dan Gould
- Payjoin fundamentals: Payjoin is an interactive protocol where sender and receiver communicate to create a single transaction with inputs from both parties, breaking Satoshi's assumption that all inputs come from one person.
- Privacy at the base layer: Dan argues Bitcoin privacy must be automatic and built into base-layer settlement, not opt-in wallet features, to achieve meaningful anonymity sets and resist surveillance.
- Async Payjoin and mailboxes: The new V3 protocol uses HTTP Oblivious HTTP with dumb public mailboxes (like Nostr relays) so sender and receiver can communicate encrypted messages without revealing IP addresses or trusting a central server.
- Why earlier privacy tools failed: TumbleBit was too early (pre-FinCEN guidance) and too complex; Wasabi coinjoins succeeded because they were simple and could monetize coordination; original Payjoin adoption stalled because it required merchants to run servers.
- Developer Kit and wallet integration: The Payjoin Dev Kit (now in Rust, Dart, Python, C#) lets wallets integrate with ~2,000 lines of code. Bull Bitcoin mobile, Cake Wallet, and others now pilot V3; more integrations expected in 2025.
- Settlement vs. payments distinction: Payjoin targets on-chain settlement between entities (exchanges, nodes, Arc providers), not everyday coffee payments (which Lightning handles). Different layers need different privacy and sovereignty models.