Interpreting the next generation of Ethereum Layer2: Booster Rollup

Source: Dengchain Community

In the first article of our Rollups 2.0 series, we discussed Based Rollup, of which based sequencing is one of the most decentralized ways and an Ethereum-compatible method for managing rollups. By handing over the task of transaction sorting to Ethereum's Layer 1, Based Rollup leverages the decentralization, simplicity, and activity of L1, among other advantages.

In today's article, we delve into the next evolution of rollup: Booster rollup. Booster rollup not only builds on the foundation laid by Based Rollup, but also pushes the boundaries of Ethereum's composability. But how exactly do we extend this composability?

What are the problems in the current L2 space?

Additional checks are often required to ensure that L2 networks operate as expected. However, the main settlement and execution processes still happen directly on L1. This means that while L2 extends off-chain EVM execution capabilities, it also adds additional complexity. Although this additional logic is not ideal, the ultimate goal is to standardize operations and rely entirely on a standard EVM.

Standardization is essential to enable smooth transaction exchange between different L2s. To achieve this goal, a new type of transaction may be needed - one that can operate across multiple chains. In this system, a transaction can create multiple smaller sub-transactions. Each sub-transaction will include details such as the source chain ID, the destination chain ID, input data (such as the caller, address, and call data), and the resulting output from the destination chain.

This transaction data plays two important roles:

1. It serves as input to the source chain, allowing participants to view outputs without directly involving the destination chain.

2. It is used on the destination chain to confirm that a given input produces the expected output.

With this approach, each chain can independently verify its own transactions while following a shared standard transaction format and inputs. Block validation is therefore kept simple, leveraging familiar L1 validation contracts to ensure the validity of blocks.

What is different about Booster rollup?

Booster rollup treats transaction processing as if it were taking place on L1, with the ability to access L1 state, but with independent storage, extending both execution and storage to L2. Each L2 expands L1’s blockspace, decentralizing transaction processing and data storage.

Imagine that you deploy your decentralized application (dapp) once, and it automatically scales to all Layer 2 (L2) networks. If you need more blockspace, just add more booster rollups, with no additional configuration required. In other words, no extra work for developers, no redeployment costs, and no additional complexity.

In layman’s terms, booster rollups are like adding an extra CPU or SSD to your laptop: they increase performance, allowing applications to run more efficiently and scale easily.

For technical readers, booster rollups can also be described as “distributing the execution and storage of transactions across multiple shards.”

How does booster rollup work?

Any rollup, whether optimistic or ZK, can adopt booster functionality. However, not all rollups need to be fully boosted, as some may benefit from L2-specific optimizations.

The best scenario for boosting is Based Rollup if the goal is to achieve native Ethereum scaling. By allowing L1 validators to propose blocks for the entire boosted network, you are essentially scaling Ethereum seamlessly.

Booster Rollup also addresses the fragmentation issue in the current rollup ecosystem. By leveraging Based Ordering, they maintain the benefits of L1 ordering while introducing atomic cross-rollup transactions within the boosted network. This setup allows for the Ethereum scaling that was originally envisioned to be achieved - integrated and broad, providing a unified solution to Ethereum's growth challenges.

Description of booster rollup architecture

Since booster rollup inherently supports synchronous composability, this rollup model eliminates the hassle of dealing with fragmentation or switching between L2s. All preferred dapps will be available on each L2, providing a seamless Ethereum experience.

With Booster Rollup, developers can scale their dapps without multiple redeployments on L2. Just deploy your dapp once on L1, and it automatically scales to all existing and future enhanced L2s, simplifying the overall development and deployment process.

Which teams are building booster rollups?

One of the few teams currently building booster rollups is Taiko Gwyneth, which is also a Based Rollup that is sync-composable with Ethereum. Gwyneth leverages Ethereum’s foundation, with transaction ordering handled by L1 validators and blocks assembled by compatible L1 builders.

Gwyneth embodies sync-composability by enhancing and extending L1 capabilities. With local ordering, it allows for smooth integration between rollups and L1 states. As block space requirements increase, deploying additional booster rollups becomes as simple as upgrading a laptop with more CPUs or SSDs to increase computing power and expand adoption. Gwyneth envisions a seamlessly integrated Ethereum without fragmentation.

Gwyneth introduces a pre-confirmation mechanism where L1 validators can commit to L2 state in advance, providing users with fast transaction confirmations and ensuring that congestion and contention costs are fairly distributed among base layer participants. This innovation continues to be driven following the pioneering work of the Taiko testnet based on pre-confirmed transactions.

From the beginning, Gwyneth was designed with finality as a goal. Powered by Taiko’s in-house multi-prover Raiko, it is designed for synchronous composability. Currently, trusted execution environments (TEEs) serve as a minimum guarantee for execution, but the future is expected to leverage optimized zero-knowledge virtual machines (zkVMs) such as SP1, Risc0, and potentially many others.

What Booster rollup means

Booster rollup transparently enhances scalability, just like adding servers to a farm. This design allows applications to seamlessly take advantage of additional resources, ensuring that developers can scale their solutions without requiring additional steps (such as deploying complex L2 infrastructure).

They solve the fragmentation problem by providing a unified experience between L1 and L2. With smart contracts sharing the same address, users enjoy consistency and simplicity whether they are interacting with L1 or L2 environments.

They solve the deployment inefficiency problem, allowing developers to deploy only once on L1, making dapps support multiple rollups by default, and updates managed by the center. Users enjoy a single address between networks, whether using EOA or Smart Wallet, facilitating seamless transactions between L1 and L2.

They solve the challenge faced by rollup operators, convincing developers to deploy on their network because dapps are automatically available. The concept is stackable, and boosters can be combined with Based Rollups to achieve significant expansion. Not all L2s need to be booster rollups, allowing for the existence of hybrid networks.

They address sovereignty and security issues by eliminating the need for specific wrapper contracts, as smart contracts work the same way on L1 and L2, maintaining developer control. Security is enhanced by applying security to each dapp, rather than relying on a bridge or specific implementation, thereby solving the problem of single points of failure.

About Limitations of Booster Rollups

To ensure that L2 mirrors L1, contract deployment should be limited to L1, ensuring uniform access across L2. This is not a major limitation, as smart contracts can still behave differently through data-driven approaches, such as storing contract addresses in storage, which may vary between different chains.

While L1 holds shared data, this does not directly increase scalability, which is an inherent challenge in scalable systems. Developers must optimize to minimize this impact. Similar to traditional software, not all dapps can take full advantage of parallel processing. However, these dapps still benefit from interoperability; although they run on a separate L2, they are still universally accessible.

Booster Rollups essentially act as an extension of the L1 chain, but with unique transaction execution and storage. To interpret Booster Rollup transactions, L1 and L2 nodes must be running in sync. However, one approach may involve running both L1 and L2 on the same node, switching between shared L1 storage and L2-specific storage during transaction execution.

Conclusion

Booster Rollups provide a transformative solution to Ethereum's scalability challenges in terms of increasing transaction throughput and storage efficiency by seamlessly integrating L1. They address issues such as fragmentation and deployment inefficiencies, enabling developers to easily scale dapps across multiple L2s while maintaining security and sovereignty. By simplifying scalability and facilitating interoperability, Booster Rollups pave the way for a more coherent and user-friendly Ethereum ecosystem.

In our next series, we will dive into the fascinating world of Native Rollups and Gigagas Rollups, exploring how these technologies can further revolutionize the Ethereum scaling landscape.