Permissionless, trustless cross-chain bridging without Oracles.
The cryptocurrency ecosystem is rapidly expanding, with new chains emerging, including L1s, L2s, side-chains, and app-chains. We envision a future where thousands of these chains exist to scale the capacity of blockchain technology to billions of users. However, this necessary proliferation creates a significant challenge: seamless asset movement across chains. This challenge also hampers the development of new chains as the user onboarding process becomes a vital issue.
Most blockchain networks are isolated by design, meaning there is no native way to transmit information from one to another. Bridging protocols are designed to overcome that isolation. They typically use Oracle-based systems to transfer and validate information across chains. Once the state is confirmed on the source chain, the information is relayed to the destination chain, where the value transfer is executed.
<aside> 💡 We use the term “Oracle-based systems” to collectively describe various solutions, from optimistic Oracles (Across) to separate settlement chains with their own relayers (Wormhole) and so-called verification networks (Stargate—LayerZero). Regardless of the specific approach, their core function is to act as an Oracle, localizing external information through 3rd parties.
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While the approach with Oracles seems reasonable (and widely adopted), it introduces several significant challenges: