POLYBRIDGE: A Crosschain Bridge For Heterogeneous Blockchains

Yue Li, Han Liu, Yuan Tan

Abstract: While the Bitcoin and Ethereum are still leading the world of permissionless blockchains, we are increasingly seeing a multipolar ecosystem where new blockchains keep emerging instead of migrating to the two big players. As a result, it is highly desired to enable multiple blockchains to interoperate, e.g., move assets from one blockchain to the other. The crosschain bridge service, as a solution to the blockchain interoperability problem, has been offered by a wide range of service providers. However, the existing bridges either rely on centralised notaries or require complicated preparations, therefore are far from sufficient in practice. In this demo proposal, we highlight the Poly Bridge for heterogeneous blockchains to interoperate with cryptocurrencies. In specific, Poly Bridge is based on an un-derlying Poly Chain and a pair of relays to confirm crosschain transactions and form consensus among relevant parties. More importantly, Poly Bridge delivers extensibility to flexibly inter-face to blockchains with different consensus models and atomicity as well in a way that a sequence of crosschain operations are either all confirmed or all rejected. Poly Bridge is now available as a web application to support crosschain requests with over 200 types of cryptocurrencies on 18 blockchains.