What makes cross-rollup interoperability a secret to win in Layer2 Era?

Blockchain ecosystem is progressing constantly, and is currently valued at $2 trillion. However, most L1s face an inherent scalability issue, making them heavily reliant on L2s to achieve speed and throughput. Although L2s have successfully maximized speed and throughput, they struggle with cross-rollup interoperability. To succeed in the L2 era, it is crucial not to let your ecosystem become isolated.

The need for the hour is to achieve both scalability and cross-rollup interoperability without compromising security. In this article, we will explore how L2s have offered diluted cross-rollup interoperability rather than the concentrated interoperability needed. Additionally, we will examine some solutions that aim to provide concentrated interoperability without the security risks posed by bridges.

The challenge of rollup interoperability

There are several reasons to consider roll-up interoperability within rollups as diluted rather than concentrated. The primary method for interconnecting different rollup ecosystems is through bridges, but bridges have fallen short in three key areas:

Creating the same level of trust as the main chain during roll-up interoperability.

Being extensible across multiple chains.

Being data-agnostic.

As a result, L2s are establishing a trust-dependent model to connect with neighboring ecosystems. However, this trusted setup introduces the risk of a man-in-the-middle (M-i-M) attack to verify transactions. The M-i-M can manipulate the code because bridges do not inherit the base layer’s security, potentially siphoning funds through multi-signature (multi-sig) attacks. This issue has already been observed with the Polygon, Ronin, and Wormhole bridges, which collectively lost over $2 billion. This is significant, considering the technology is still new and at an early stage of adoption.

Hence, it is essential to ensure that cross-rollup interoperability and usability occur simultaneously and with absolute security. This entails enabling different rollups, regardless of their underlying technology stack, to communicate in a trust-minimized manner and overcome the interoperability trilemma.

This objective can be achieved through solutions that guarantee immutable, permissionless, and censorship-resistant connections with the roll-up networks. Let’s examine how some protocols are accomplishing this in their distinct ways.

A dive into top protocols and their approach to solve interoperability issues

LayerZero

LayerZero uses the Decentralized Verifier Network (DVN) as a Quasi Aggregator. The protocol addresses the challenge of verifying messages across chains in a quasi-linear manner, enabling developers to send arbitrary data, external call functions, and tokens while retaining full control over their applications and facilitating roll-up interoperability. This approach restores developers’ sovereignty while facilitating omni-channel communication with the roll-up network.

In essence, LayerZero is similar to the TCP/IP of blockchains, facilitating seamless communication with other rollup networks in a permissionless, decentralized, censorship-resistant, and immutable manner. LayerZero achieves this through the Omnichain Fungible Token (OFT) Standard, which enables developers to extract token balances across multiple supported blockchain ledgers.

The OFT Standards add an additional layer on top of the protocol consensus layer to track asset movements across partner networks. This empowers users to debit a token from one chain and credit it to another chain through a messaging protocol layer that provides ZK-proofs of events without requiring token locks on vulnerable bridges from the source and destination chains.

LayerZero utilizes the Decentralized Verifier Network (DVN) as a Quasi Aggregator. It addresses the challenge of verifying messages across chains in a quasi-linear manner, enabling developers to send arbitrary data, external call functions, and tokens while retaining full control over their applications and facilitating roll-up interoperability. This approach restores developers’ sovereignty while facilitating omni-channel communication with the roll-up network.

In essence, LayerZero can be likened to the TCP/IP of blockchains, facilitating seamless communication with other rollup networks in a permissionless, decentralized, censorship-resistant, and immutable manner. LayerZero achieves this through the Omnichain Fungible Token (OFT) Standard, which enables developers to extract token balances across multiple supported blockchain ledgers.

The OFT Standards add an additional layer on top of the protocol consensus layer to track asset movements across partner networks. This empowers users to debit a token from one chain and credit it to another chain through a messaging protocol layer that provides ZK-proofs of events without needing the token locks on vulnerable bridges from the source and destination chains.

Hyperlane

HyperLane, similar to LayerZero, employs a distinct form of interchain communication called the interchain security model. This model sits atop the consensus, execution, settlement, and DA layers, granting developers complete control to design, customize, and configure their security model according to their project requirements for communication with various rollup environments. The Interchain facilitates the development of interchain applications that aggregate multiple blockchains and bundle them together through the Interchain highway, which is built on top of a modular stack.

The Interchain highway packages the data and transmits it to the mailbox, which then forwards the data to the destination chain to initiate an execution for a state change. The mailbox functions as a chain aggregator, responsible for tracking events across multiple blockchains in a trustless manner. Typically, events are relayed in the form of bytes and codes for verification. Subsequently, the underlying security module employs validators, optimistic systems, watchtowers, and ZKs to verify the transaction.

Following this, relayers serve as decentralized networks that transmit data across different chains to trigger state executions on both the source and destination networks in a genuinely peer-to-peer, secure, and decentralized manner. HyperLane’s modular approach enables developers to utilize their own security models instead of adhering to a one-size-fits-all approach, ensuring the protection of cross-rollup interchain communication.

Axelar

The Axeler protocol leverages the Cross-Chain Gateway Protocol (CGP) and Cross-Chain Transfer Protocol (CTP) to facilitate seamless cross-chain rollup interoperability communication through smart contracts. Any chain can connect via the CTP protocol, which utilizes API calls similar to HTTP GET/POST requests. By eliminating the need for integration at the protocol level, developers can easily plug and connect using an API protocol, accessing global liquidity spread across chains and enabling effortless cross-bridging of different rollups without complexities.

Unlike other blockchains such as Cosmos, which require centralized systems, interoperability hubs, and pairwise bridges to connect with different blockchains, the Axelar protocol simplifies this process. It is essential that the blockchains are developed on Tendermint, but Axelar protocol enables this without the reliance on a single programming language for communication across different blockchains. With Axeler’s Interchain Amplifier and Maestro, setting up the Axelar protocol and connecting your dApp across different cross-chain rollups to interoperate with your partner network can be accomplished with just one click. The advantage of Axeler lies in its ability to facilitate one-bridging to connect with numerous chains simultaneously, a feature that sets it apart from other interoperability protocols.

Router Protocol

The Router Protocol has introduced the concept of intent to facilitate bridging between different chains in a user-friendly manner. Through the Cross-Chain Intent Framework, the Router protocol seamlessly simplifies cross-rollup interchain communication by allowing users to express their intent, which smart contracts can then use to trigger state executions proactively.

To illustrate, Router utilizes a prompter to discern user intent, enabling it to execute transactions on their behalf. For instance, if a user wishes to swap 1000 DAI for ETH at the best rates, the Router Protocol searches across various protocols, matches the order, and executes the transaction on behalf of the user, offering a transaction experience akin to Web 2.

Currently, users seek simplicity in their Web 3 interactions, and Router has streamlined this process by allowing users to provide prompts and swiftly accomplish tasks. This approach not only simplifies cross-rollup interoperability but also elevates the user experience to a level comparable to that of Web 2, emphasizing simplicity and efficiency.

Add Interoperability to your rollups with Zeeve

Zeeve stands as the premier platform for Rollups-as-a-service (RaaS)solutions, offering a comprehensive network of trusted 3rd-party integration partners. Among these solutions, Cross-rollup Interoperability stands out prominently. Each of the interoperability protocols mentioned earlier is readily accessible as an easily integrable component for optimistic or ZK rollups deployed through Zeeve RaaS. Rollup developers can select the interoperability protocol that best aligns with their requirements, whether it be zkSync ZK stack, Polygon CDK, Arbitrum Orbit, or OP Stack, all of which seamlessly integrate with any rollup frameworks available on Zeeve.

In addition to interoperability tools, Zeeve offers a plethora of pluggable components including decentralized sequencers, DA layers, oracles, privacy and security tools, and account Abstraction SDKs.

If you’re planning to launch your own rollups, feel free to reach out to us. Our experts are equipped to assist you in identifying the most suitable infrastructure for your use case. Schedule a call with us today!