“Bitcoin exists to remove intermediaries from the movement of money online. Without privacy, if someone can see how money is moving, they don't like someone you paid, they can discriminate based on that.” — Dan Gould
Dan Gould builds PayJoin, the privacy protocol that breaks Bitcoin surveillance while cutting transaction fees up to 25%. Satoshi flagged Bitcoin's privacy problem in the white paper—PayJoin solves it without mixing, turning surveillance assumptions into dead ends. When privacy becomes an economic benefit rather than a cost, adoption follows.
Episode Summary
Dan Gould reveals how PayJoin breaks the core assumption that chain surveillance companies use to track Bitcoin users across the network. By allowing both sender and receiver to contribute inputs to a transaction, PayJoin shatters the multi-input heuristic—the dragnet surveillance tool that assumes all inputs come from the same person. This isn't just privacy theater: PayJoin delivers up to 25% fee savings while protecting financial activity from arbitrary discrimination. Gould explains why Bitcoin's Fourth Amendment moment hasn't arrived yet, how interactive batching supercharges both privacy and efficiency, and why merchant adoption creates network-wide privacy improvements even for users who aren't running PayJoin. The protocol requires no trust in third parties, no heavy dependencies like Tor, and works asynchronously so participants don't need to be online simultaneously. With integrations rolling out across wallets and exchanges, PayJoin shifts privacy from an expensive add-on to a default cost reduction. Privacy, cost savings, censorship resistance—or you can keep broadcasting your transaction history to chain surveillance firms.
About the Guest
Dan Gould is maintainer of PayJoin Dev Kit, a privacy-focused Bitcoin development toolkit supported by OpenSats and Spiral. He launched PayJoin Foundation with eight independent contributors and a volunteer board to eliminate the server requirement that blocked widespread adoption of privacy-preserving Bitcoin transactions. Gould's work on serverless PayJoin (BIP 77) enables asynchronous transaction coordination through encrypted messages, removing the barrier that prevented mobile wallets and merchants from implementing the protocol. His approach treats privacy as infrastructure rather than luxury—breaking surveillance heuristics while reducing fees makes adoption inevitable rather than aspirational.
Social Links:
Key Quotes
Key Takeaways
Timestamps
[00:00] Why PayJoin works like HTTPS—making surveillance unreliable across the network
[02:11] PayJoin Foundation launch: Eight contributors building privacy infrastructure
[04:30] How exchanges batch withdrawals to reduce fees without sacrificing privacy
[08:32] Bitcoin's Fourth Amendment gap—why digital cash has less protection than physical
[14:42] Breaking the multi-input heuristic that enables dragnet Bitcoin surveillance
[20:15] Interactive batching supercharges Bitcoin transactions with privacy and cost savings
[27:45] Why merchants get fee benefits while improving customer privacy
[35:20] Cross-input signature aggregation delivers 25% fee reduction with privacy
[42:18] Serverless PayJoin removes infrastructure barriers through encrypted mailboxes
[48:30] Lightning integration: PayJoin for channel opening and splicing
[52:26] Essential privacy hygiene for self-custody Bitcoin users
[54:27] How developers integrate PayJoin into wallets and e-commerce platforms
[56:17] Six-month roadmap: Production integrations and multi-party PayJoin advances
Resources & Links
Projects & Organizations:
Referenced Technologies:
Mentioned Organizations & Projects:
Podcast:
