Sui Bridge: An Innovative Solution for Cross-Chain Asset Transfer

Sui Bridge, as the native bridge of Sui, provides a highly trusted channel for the cross-chain transfer of Sui assets. In recent months, the development of Sui Bridge has made significant progress, enhancing the accessibility of the Sui ecosystem and improving interoperability with other blockchains.

As a core component of the Sui ecosystem, Sui Bridge facilitates the secure and efficient transfer of assets and data between Sui and other blockchain networks. This functionality not only expands the reach of applications built on Sui but also provides a pathway for deeper integration into the broader blockchain environment. The enhancement of interoperability drives the growth and adoption of Sui, allowing assets from other networks to be securely and conveniently migrated to the Sui platform.

Overview of Sui Bridge

In the blockchain ecosystem, cross-chain bridges are protocols that allow interaction and communication between independent blockchain networks. They facilitate the transfer of cross-chain data, enabling users to move assets from one chain to another and even perform more complex operations, such as cross-chain messaging.

Among the various cross-chain bridge design options, Sui Bridge adopts a locking and minting mechanism, which is one of the most widely used solutions. As a locking and minting design, Sui Bridge holds Ethereum native assets within Ethereum smart contracts, while in the direction of the bridging interaction, Sui assets will be minted or burned.

Sui Bridge, as the native bridge of Sui, does not require additional trust assumptions. It is secured by nodes of the Sui network, and its code has been integrated into the Sui framework. Currently, Sui Bridge is available on the testnet, supporting bridging tokens such as ETH, WETH, WBTC, and USDT between the Ethereum Sepolia and Sui testnets. Future versions of Sui Bridge will add new features, such as custom cross-chain messaging and integration with other blockchains.

Advanced Architecture

Sui Bridge consists of four key components: the Sui Bridge committee or node network, the Sui Bridge smart contract, full nodes running on Ethereum and Sui, and the bridging client.

The client serves as the interface between the user and the Sui Bridge infrastructure, coordinating the user's bridging operations by submitting correctly formatted transactions and collecting Sui Bridge node signatures. It uses full nodes to submit transactions on both sides of the bridge. Sui Bridge nodes also run Ethereum and Sui full nodes to listen for bridging operations and respond to these operations with subsequent transactions.

When bridging from Ethereum to Sui, users deposit assets into the Sui Bridge smart contract on Ethereum. The client then observes the transaction and coordinates the bridging process. The Sui Bridge committee operates a full Ethereum node to listen for such bridging operations to verify the legitimacy of client requests. Upon verification, bridging assets are minted for the user through the Sui Bridge package on Sui, thereby completing the bridging operation.

The process of bridging from Sui to Ethereum is similar, but users need to manually submit a claim transaction on Ethereum. This transaction includes the signed data from the Sui Bridge node, allowing the Ethereum account to redeem the specified assets locked in the bridging contract.

Bridging Message

Sui Bridge is designed with a lightweight message format that is easy to decode by receiving chains to ensure low gas fees. It uses a universal message format that ensures each chain can efficiently decode and verify messages and signatures. This simplified design reduces complexity and computational overhead, ensuring low gas fees while facilitating fast and reliable cross-chain communication.

Bridge Security

Sui Bridge inherits the decentralized node operator network of Sui, which has the capability to run and protect the Sui infrastructure. Most Sui Bridge operations are conducted on Sui, viewing Sui as the control panel of the bridge, thus inheriting the security features of the software developed using the Move language.

Bridge Committee

Sui Bridge is protected by the same set of validator nodes that ensure the security of Sui. During the testnet phase, the committee is composed of some testnet validator nodes. After the mainnet goes live, most (if not all) active Sui validator nodes will become part of the bridging committee.

signature verification

Sui Bridge uses recoverable ECDSA signatures, allowing the public key to be recovered directly from the signature. A message is only considered valid when the total weight of the signatures meets or exceeds a predetermined threshold. This mechanism ensures that a sufficient number of authenticated signatures are required to verify the message, thereby enhancing the security and reliability of the system.

Build Interoperability

The Sui native bridge not only provides a secure and efficient means of transferring assets between blockchain networks, but also lays the foundation for more advanced cross-chain interactions. By leveraging its powerful trust model, integrating ECDSA for secure and verifiable transactions, and adopting a committee-based signature verification process, the Sui Bridge ensures high security and reliability while maintaining flexibility.

With the development of the ecosystem, the bridge will support a wider range of assets and functions, such as customizable cross-chain messaging, allowing for unique cross-chain interactions. The Sui Bridge represents a significant advancement for Sui in the field of interoperability, providing users with a seamless and highly secure cross-chain asset transfer solution.