1 sat \ 8 replies \ @cointastical 8 Jan 2022 \ on: A multisig P2P Bitcoin trading platform - Hodl Hodl bitcoin
Lightning network ⚡ can be used, as a payment method, on HodlHodl. This means you can:
- Buy bitcoin and pay using LN ⚡ <-- i.e., swap your LN ⚡ for BTC on-chain
- Sell bitcoin and receive on LN ⚡ <-- i.e., swap your BTC for LN ⚡
same for Liquid network 🌊 -- Liquid Bitcoin is a payment method on HodlHodl (as-is Liquid Tether (USD), and Liquid CAD.
- Buy bitcoin and pay using Liquid Bitcoin 🌊 <-- i.e., swap your L-BTC 🌊 for BTC on-chain
- Sell bitcoin and receive Liquid Bitcoin 🌊 <-- i.e., swap your BTC for Liquid Bitcoin 🌊
Super pumped that they added lightning support again. Do you know when they did that? I missed the news.
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They used to have (custodial) LN as the trading currency. When that was enabled, you could list a SELL offer where bank transfer was the payment method, for example. So a trade for that involved no on-chain bitcoin transactions.
HodlHodl has not re-implemented that, they simply added LN as a payment method.
The hurdle for HodlHodl is that there's (currently) no easy way to escrow the LN without doing it custodial, and HodlHodl does not want to be a custodial platform whatsoever.
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Oh, that's fun. I'd like to know more technically about the implementation. I couldn't find any bids/offers on the site and can't see any technical docs (maybe they're there but in a few minutes, I couldn't find them).
HodlHodl is using 2 of 3 and holding a third key as escrow/arbiter, is that correct? For the LN case, are they keeping that model or somehow arranging a submarine swap construction? If the former, how are they doing proof of payment, exactly? If the latter (I doubt it), I'd be interested in the exact construction.
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HodlHodl simply added LN as a payment method.
So the offers are all still just offers to BUY BTC (on-chain) or offers to SELL BTC (on-chain). Nothing changed -- seller's BTC goes into multisig escrow, buyer sends LN payment, seller releases BTC escrow. If there's a dispute where seller claims buyer didn't pay the LN invoice, that's a normal LN method to prove whether or not that is true (using the preimage).
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Oh that's true, there's a subtlety: I was remembering the fact that you can't prove that you paid, and not someone else, (because others on the route have a preimage), but here that's irrelevant, because arbitration will only require proof that the payment is made, not that a specific person did so.
Hopefully we get more sophisticated in future, though I didn't expect it yet: there is no good reason not to use on/offchain swap markets for this kind of thing (they kinda already exist, but I don't think any are p2p(?)).
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The hurdle to providing on/offchain swap P2P is that there's (currently) no easy way to escrow the LN without doing it custodial.
If you see the "Crypto-to-crypto methods" of this list includes three P2P exchanges, but the two non-custodial, Bisq and HodlHodl, provide LN only as pmt method, and the remaining one is custodial ... they let you deposit and withdraw with LN, and you pay a fee (1%) when withdrawing BTC via LN.
Exchanges With LN:
https://github.com/cointastical/Exchanges-With-LN
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In reviewing that, ... it looks like Bisq does not support LN even as a payment method. There is a fork of Bisq, "Misq", ... or even Bisq 2.0, in-development that will handle multiple protocols, including LN.
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