11 czerwca 2024 10:15
[Seminarium ZOK] Marek Chrobak: On HTLC-Based Protocols for Multi-Party Cross-Chain Swaps
Abstract: In his 2018 paper, Herlihy introduced an atomic protocol for
multi-party asset swaps across different blockchains. His model
represents an asset swap by a directed graph whose nodes are the
participating parties and edges represent asset transfers, and
rational behavior of the participants is captured by a preference
relation between a protocol's outcomes. Asset transfers between
parties are achieved using smart contracts. These smart contracts are
quite intricate and involve solving computationally intensive graph
problems,limiting practical significance of his protocol. His paper
also describes a different protocol that uses only standard hashed
time-lock contracts (HTLC's), but this simpler protocol applies only
to some special types of digraphs. He left open the question whether
there is a simple and efficient protocol for cross-chain asset swaps
in arbitrary digraphs. Motivated by this open problem,we study
HTLC-based protocols, in which all asset transfers are implemented
with HTLCs. Our main contribution is a full characterization of swap
digraphs that have such protocols.
Joint work with Emily Clark, Chloe Georgiou and Katelyn Poon.