⚡️DailyZap: Censorship-Resistant Permissionless Lightning Exchanges On Nostr A very interesting whitepaper dropped into the Bitcoin-Dev mailing list last week. The idea behind Civ Kit is to use Nostr and Bitcoin/Lightning together to create a "censorship-resistant and permissionless global trading" system that everyone can access. The whitepaper is very well written, with clear yet concise explanations of the various technological pieces involved, as well as the potential pitfalls of such a system and how they can be mitigated. Well worth a read, but here's a quick summary anyway. A maker who wishes to partake in a certain trade (for example, exchange 0.1 BTC against 10,000 Kamas) creates a Lightning Offer containing all the details of the trade (amounts, expiry period, oracle, escrow, etc.) and sends it to one or many bulletin board(s) via Lightning Onion Messages. Bulletin boards are also Nostr relays and, when one receives a trade offer, it broadcasts it to all the subscribed clients. Among those clients, if one of them finds the offer interesting and wants to take it, they do so by sending a specifically-crafted HTLC to the maker's blinded endpoint, which they specified in their Offer. From then on, the taker is committed to the trade, and either the maker is still interested and the trade happens, or the maker just lets the HTLC expire and the taker gets their funds back. Already sounds a bit too complicated? Here's an even simpler explanation. Someone wants to trade, they send the details of the trade they're looking to make to a Nostr relay, which broadcasts the trade offer to everyone listening. Among the listeners, someone interested can then directly initiate the trade. That's it. The rest of the explanation only describes which communication medium is used where and why, to ensure both privacy for the participants and resiliency for the bulletin boards. For example, using Lightning Onion Messages to send the trade offer from the maker to the bulletin board in the form of an Offer helps protect bulletin boards from DoS attacks, as they can enable rate-limiting based on amounts deployed in direct channels, while protecting the maker's privacy at the same time. On the other hands, Nostr totally makes sense as a publication network. Finally, complex Bitcoin contracts (for example involving escrows using multisignature schemes) can be used to perform the trade itself, either on-chain or off-chain, where such contracts can even be routed across the Lightning Network. Of course, we are at the very beginning of the specification process of this idea, but it feels really powerful. Part of this feeling I think comes from the apparent simplicity of the system, while it will require many more building blocks to make it actually resilient and censorship-resistant, such as privacy-preserving stake certificates (a bit like the ones proposed by Riard to solve channel jamming) to enable participants to assess whether a trade counterparty is "trustworthy" or not. At this point, I really hope you're as pumped as me. This is really an exciting subject, as the number of similar projects being built right now demonstrates. For example Francisco Calderón shared their advancement on Mostro (which we briefly covered here) last week. The core functionality is operational, and the team is working on orders cancellation, dispute logic and a reputation system. Mostro works quite like Civ Kit in the sense that a maker sends a trade offer to a relay (a Mostro instance) which broadcasts it to listeners. Big differences are that all communications (order publishing, order taking, reputation scores) happen on Nostr, and that Mostro instances serve as escrows to settle trades between users (whereas on Civ Kit the bulletin board's role stops at broadcasting the offers it receives). The team is looking for contributors, so feel free to check out their website. Another alternative proposal is n3xb, which stands for "Naive Nostr No-KYC Exchange". As the name suggests n3xb focuses on simplicity, in a stance not to dissimilar to the one that underpinned Nostr's design itself. All communication happens on Nostr, using a special kind even for trade offers and relays to broadcast them to the public. When a taker wants to partake in the trade, they send a Nostr DM to the maker to notify them and send the finalized details of the contract, which initiates the trade if the maker accepts. All this various proposals are very cool. Some are more complex because they try to address complicated problems such as DoS mitigation from the get go, while others focus more on simplicity. Really looking forward what builders will come with in the coming months! 🔗 Links: Civ Kit: A Peer-to-Peer Electronic Market System: lists.linuxfoundation.org/pi… Read more: blog.lnmarkets.com/latest-st…