Paradigm and Across Protocol researchers outline plan for capital-efficient 'intents-based' bridge

Crypto researchers have introduced a new design for a capital-efficient, trustless, and fast blockchain bridge using the cross-chain Across Protocol.  

Called Across Prime, the “intents-based” bridge uses “relayers to send payments faster than the speed of cross-chain messages,” Paradigm general partner Dan Robinson wrote in a X post on Tuesday. 

A white paper co-written by Robinson, Hart Lambur, and Matt Rice explains that Across Prime uses a “bonded bridging model” where relayers secure users' origin chain payments by depositing funds to fulfill actions on the destination chain. Lambur and Rice are co-founders of the inter-blockchain Across Protocol.  

In other words, users will send their tokens directly to a relayer on the origin chain, which is then responsible for fulfilling the user's intended action on the destination chain. This direct payment eliminates the need for locking assets in an escrow contract, which is common in traditional bridges and can tie up significant capital.

The arrangement is theoretically more secure and scalable than traditional bridges, which are a frequent point of attack by exploiters. For instance, the Wormhole and Ronin bridge attacks are among the largest crypto attacks to date. 

Relayers will secure these transactions by depositing a so-called “security bond” as collateral in a smart contract. This bond ensures that relayers act honestly and fulfill the user's request on the destination chain. If a relayer fails to deliver the promised assets on the destination chain, the bond can be slashed to compensate the user.

Once the transaction is confirmed on the destination chain, the bond is reusable for future transactions. The white paper co-authors argue that this is a more capital-efficient system than escrow-based models that lock up funds for each transaction.

“Intents” frameworks aim to improve crypto UX and are a growing though largely experimental field today. These systems allow users to specify desired blockchain uses, which are then carried out on their behalf. Relayers compete to fulfill these intents optimally.

Across Prime operates similarly to the Across Protocol’s existing bridge but introduces a new bonded model to reduce capital requirements. The Across Protocol is a cross-chain solution aiming to connect Ethereum Layer 2 ecosystems like Arbitrum, Optimism, and Polygon.