CoB

As crypto becomes increasingly multichain, it is crucial to have a reliable method to transfer canonical funds between chains. However, most existing token bridges are extremely prone to vulnerabilities that can lead to the loss of funds, as well as being costly for users.

CoB aims to solve this by providing a secure and extremely inexpensive method of bridging: by finding Coincidences of Bridging between users on different chains.

CoB can be utilized for both cross chain asset transfers and cross chain swaps. Users submit their cross chain orders to CoB, and the contract matches orders of the same type together to provide a seamless and secure transfer.

CoB is a Solidity smart contract with deployments on Polygon zkEVM testnet, Ethereum Sepolia, Base Goerli, Arbitrum Goerli, and Scroll Sepolia. The main protocols powering CoB are Hyperlane for cross chain messaging, Chronicle for swap pricing, and ENS for streamlined oracle processing.

When a user submits an order to CoB, the contract first checks if the order can be filled against existing pending orders. If yes, the order will attempt to fill as many orders as it can, with the filled order tokens sent to the respective parties on their respective chains. After this is complete, or in the case where there were no pending orders available, a message is broadcasted to the destination chain using Hyperlane where they become a pending order until another coincidence of bridging is found.

Additionally, for cross chain swaps, we built a custom router contract to resolve asset pair prices through ENS & Chronicle. For example, when a user wants to perform a cross chain swap of ETH to USDC, the router will fetch the Chronicle pricing of this pair through ETHUSD.cob.eth and USDCUSD.cob.eth. The prices fetched from Chronicle are then used for the exchange rate between the two assets.