Learning Bitcoin and Design: PayJoins

[sbddesign]

Date: 2022-12-13
Time: 5:00pm
Timezone: UTC
Duration: 1h
UTCTime: 2022-12-13 17:00 UTC

Agenda

This call is intended to help you learn new concepts about Bitcoin, Lightning, and design. The general format will be to focus on a specific topic or read-through a document together and discuss (like a chapter of the Design Guide, or something that will help us learn about Bitcoin and Lightning).

On this call, we'll focus on PayJoins, which is a technique for improving privacy on bitcoin. Dan Gould will join us to help us discuss this topic.

Check your timezone

https://everytimezone.com/s/f696ffe5

Join the call

https://meet.jit.si/bitcoindesign

Calendar invite

Subscribe to the Bitcoin Design calendar. More info here.

[DanGould]

I got some feedback in the BOLT FUN design discord:

Me: Any designer have ideas why payJoins might have relatively low software adoption so far?
617a7a: People shouldn’t even know they’re happening. Most people don’t care
617a7a: Any privacy benefits should be added without additional UX steps
Me: Indeed this why I think PayJoin is a great solution. It works inside a unified QR code. Did you know that or is there some other experience you've had with PayJoin in the past that required more steps?

I have a feeling people might be misinformed that PayJoin is a synchronous protocol with lots of waiting like zerolink CoinJoins. Yes, it requires parties to be online, but that hasn't stopped lightning from taking off

[sbddesign]

We are going to reschedule this for same time next Tuesday (December 13th). Apologies for the last minute time change!

[DanGould]

In preparation here is a collection of language & experience records relating to PayJoin & P2EP

Please feel free to add more https://docs.google.com/document/d/1y5qiKEX2WXMoDgdNclKcZ2RHDIM8wX5OkhREA-Hmc0k/edit#

[DanGould]

Another idea we should touch on is the idea of pull-payjoins. The current bip 78/79 model requires a receiver to host a secure endpoint to establish sender-receiver communications. What if the sender is a service already and it's easier for them to host?

[sbddesign]

Here is the recording of yesterday's call:

• YouTube
• BitcoinTV

Here are notes:

• Dan's document
• FigJam file with in-call notes