From 861dcc4a56e827ee49125be15a9a3b60f4db3d74 Mon Sep 17 00:00:00 2001 From: "Tobin C. Harding" Date: Fri, 9 Oct 2020 09:34:24 +1100 Subject: [PATCH] Update README Update the readme inline with review suggestions by doing: - Copy 'long story short' text from blog post - Correct the erroneous description of watching blockchains - Fix gramar --- README.md | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/README.md b/README.md index 20683206..f5a58518 100644 --- a/README.md +++ b/README.md @@ -3,6 +3,21 @@ XMR to BTC Atomic Swap This repository is a proof of concept for atomically swapping XMR for BTC. +In the best-case scenario the protocol looks like this: + +1. Alice and Bob exchange a set of addresses, keys, zero-knowledge proofs and signatures. +2. Bob publishes `Tx_lock`, locking up his bitcoin in a 2-of-2 multisig output owned by Alice and Bob. +Given the information exchanged in step 1, Bob can refund his bitcoin if he waits until time `t_1` by using `Tx_cancel` and `Tx_refund`. +If Bob doesn't refund after time `t_1`, Alice can punish Bob for being inactive by first publishing `Tx_cancel` and, after `t_2`, spending the output using `Tx_punish`. +3. Alice sees that Bob has locked up the bitcoin, so she publishes `Tx_lock` on the Monero blockchain, locking up her monero in an output which can only be spent with a secret key owned by Alice (`s_a`) *and* a secret key owned by Bob (`s_b`). +This means that neither of them can actually spend this output unless they learn the secret key of the other party. +4. Bob sees that Alice has locked up the monero, so he now sends Alice a missing key bit of information which will allow Alice to redeem the bitcoin using `Tx_redeem`. +5. Alice uses this information to spend the bitcoin to an address owned by her. +When doing so she leaks her Monero secret key `s_a` to Bob through the magic of adaptor signatures. +6. Bob sees Alice's `Tx_redeem` on Bitcoin, extracts Alice's secret key from it and combines it with his own to spend the monero to an address of his own. + +BTC/XMR Atomic Swap Protocol + We define: - Alice to be the actor that initially holds XMR. @@ -24,14 +39,14 @@ Currently we have a single test function that proves the following: - Interaction with both block chains and their respective wallets works. - The messages required are correct and can manually drive the state transitions to execute a swap. - +- It is possible to interact with and watch the monero blockcahin using `monero-wallet-rpc` +- It is possible to watch a bitcoind instance using `bitcoin-harness` (we already knew this :) Currently we do not do: - Actual network communication. -- Watch the blockchain for transactions (we just assume they have been mined as soon as we broadcast and move onto the next state). - Verification that the UI is acceptable. -Since we do everything in a single test function their is no user interaction, this is unrealistic for a real product. +Since we do everything in a single test function there is no user interaction, this is unrealistic for a real product. ## Testing