LayerZero to Provide Cross-chain Interoperability for Astar zkEVM

What do we mean by Interoperability?

Cross-chain message networks and cross-chain asset bridges are two kinds of blockchain interoperability solutions often referred to as ‘bridges’, though they differ in their use-cases and scope of operations. All cross-chain message networks support asset bridges, however, not all asset bridges are based on cross-chain message networks. Does that sound confusing? Let’s break it down a bit more.

To simplify things we can boil the differences down to complexity, where Asset Bridges are fairly self-explanatory and useful for the transfer of assets, Message Networks are a little more ambiguous due to their myriad number of potential use-cases — basically any interaction or function you can possibly imagine across chains, including asset transfer, can be carried out by a message network.

While it may seem obvious to some that LayerZero supports the Stargate asset bridge for Astar Network and ability to easily transfer assets between Astar zkEVM and Astar Substrate parachain, as well as a number of other networks, LayerZero’s underlying Message Network that acts as the foundational layer for the asset bridge is capable of so much more. Asset transfer is only the tip of the iceberg and a kind of tech demo in terms of its potential and what is actually possible development-wise.

Asset bridges are usually composed of independent sets of smart contracts and liquidity pools residing on different chains that are generally incompatible with one another. So for example, if you use bridge A to mint a synthetic asset on some destination chain, though the original native asset may be recognized by bridge B, it may not recognize bridge A’s synthetic representation of that asset on the destination chain.

Message networks work on somewhat of a lower level by implementing a communications protocol between dApps and chains, so they can interoperate with one another and unify resources, such as liquidity pools.

How do cross-chain asset bridges work? and is it fair to compare them to Message Networks?

Cross-chain asset bridges (aka ‘bridges’) are designed specifically for transferring assets between different blockchain networks. They allow a cryptocurrency or token to be locked in a smart contract on one blockchain and a corresponding amount of a synthetic asset to be minted or unlocked on another, often denominated with a prefix such as L (for a LayerZero synthetic asset) or W as another example, for wrapped BTC (wBTC). This process enables users to move assets across blockchains that are otherwise incompatible with one another, though those assets may not be compatible from bridge to bridge on the same chains.

Why are Message Networks preferable to ‘Bridges’?

Cross-chain message networks are designed to enable general communication between blockchain networks and can handle not only asset transfers but also more complex interactions such as calling smart contracts across chains, sharing data, and triggering events. This broader functionality makes them more versatile than asset bridges, allowing them to fulfill a variety of use-cases, opening up the possibility for more complex decentralized applications that leverage the unique advantages of multiple chains.

I just want to get my ASTR over to Astar zkEVM. What else is there to do across blockchains?

There is exciting potential for many different cross-chain use-cases powered by LayerZero’s cross-chain message network, not only bridging ASTR from one blockchain to another. In the future we will see plenty of examples of:

• Asset Bridges: Stargate officially supports Astar Network and the zkEVM.
• Liquidity Sharing: LayerZero can allow DeFi platforms on different blockchains to share liquidity. For instance, a lending platform on Astar parachain could lend assets to a borrowing platform on Astar zkEVM, increasing capital efficiency across the ecosystem.
• Cross-Chain Swaps: Exchange assets between chains directly without needing a centralized exchange or taking multiple steps through intermediary bridges, eliminating five or more steps compared to the typical new chain onboarding process (obtaining the native asset). This will simplify the user experience and reduce transaction costs.
• Cross-Chain NFT Marketplaces: Artists and collectors can mint, buy, and sell NFTs across multiple blockchains. LayerZero could enable a seamless marketplace where NFTs on Astar parachain can be traded with those on Ethereum or any of their other supported networks, for example, broadening accessibility of the market.
• NFT Use Across Games and dApps: NFTs created in one game on a particular blockchain can be used in another game on a different blockchain, enhancing the utility and value of NFTs as interoperable digital assets.
• Cross-Chain Governance & DAOs: DAOs operating on one blockchain can make decisions or vote on proposals that affect another blockchain. For example, a DAO on Astar zkEVM could vote to fund a project on Astar parachain, with LayerZero facilitating the transfer of funds and execution of the decision across chains.
• Interoperable Smart Contracts: Developers can build complex multi-chain applications that operate across multiple blockchains, leveraging the strengths of each. For example, a dApp might use Polkadot for secure and decentralized governance, Astar zkEVM for faster transactions, and IPFS for decentralized storage, with LayerZero coordinating operations across these platforms.
• Load Balancing Across Chains: Applications can distribute their workload across multiple blockchains to improve scalability and reduce gas fees. For example, a heavily used dApp could perform transactions on a less congested blockchain while maintaining its presence on another.
• A Unified User Experience: LayerZero technology can be used to offer users a seamless experience by abstracting away the complexity of interacting with multiple blockchains. Users can have a single interface to access services and assets across diverse blockchain ecosystems.

These are just a few examples that illustrate the potential of cross-chain message networks to create a more interconnected, efficient, and innovative blockchain landscape, enabling use cases that were previously difficult or impossible to achieve with single-chain or simple asset bridge solutions, and that defy the ability to simply be copy-pasted from one chain to another.

So, while cross-chain asset bridges are useful for straightforward asset transfers between blockchains, cross-chain message networks such as LayerZero offer broader interoperability by enabling a wide range of messages and interactions between chains, making it a more flexible and powerful tool for building complex, inter-blockchain applications. We are excited to start seeing LayerZero-powered dApps and experiences on Astar zkEVM!

Learn more about LayerZero: https://layerzero.gitbook.io/docs/layerzero-v1/introduction

Start building cross-chain dApps: https://layerzero.gitbook.io/docs/faq/getting-started

Learn how to bridge assets to Astar zkEVM: https://docs.astar.network/docs/use/zkevm-guides/Bridge-Astar-EVM

Start bridging with Stargate: https://stargate.finance/transfer

About LayerZero

LayerZero is an interoperability protocol that connects over 50 blockchains, allowing developers to build seamless omnichain applications, tokens, and experiences. The protocol relies on immutable on-chain endpoints, a configurable Security Stack, and a permissionless set of Executors to transfer censorship-resistant messages between chains.

About Astar zkEVM

In the global web3 industry, Ethereum Layer 2 and ZK technologies are currently attracting significant attention. Astar zkEVM is a blockchain network developed and provided by Astar Network in partnership with Polygon Labs, a global player in the Web3 space, as an Ethereum Layer 2 incorporating ZK technology.