Considering Superchain Interoperability: Technical Challenges and Suggestions for Improvement at Roll Up Union
Optimism Superchain in depth from a technical perspective.
Good morning.
Mitsui from web3 researcher.
Today Crypto Crypto contributed to this article.He took an in-depth look at "Optimism Superchain" from a technical point of view.
Introduction: Challenges and Possibilities of Superchain
1. Overview of Superchain
2. How finality works
3. Understanding finality reorganization risk
4. Improvements under consideration
5. Summary: SuperchainFuture Prospects for the Ecosystem.
introduction: challenges and possibilities of superchain
Layer 2 technology, an emerging scaling solution for Ethereum, is a revolutionary mechanism for streamlining transaction processing in the blockchain.The idea of delegating transaction processing to a dedicated roll-up chain and relying on the security and decentralization of the Ethereum itself to keep it secure while improving performance has contributed significantly to the development of the entire Ethereum ecosystem.
However, when looking at individual roll-up chains, the situation is more complex: as of 2024, there are approximately 100 roll-ups in operation, and competition is already intensifying and weeding out the best of the best.One survival strategy is to form a union of roll-up chains that use the same development infrastructure framework, and the "Superchain," a group of roll-up chains based on OP-Stack, is a particularly noteworthy union.This ecosystem has attracted the attention of companies and emerging projects, with major projects such as Optimism, Base, World Chain, and Manta Network.Its growth has also been noteworthy, with major companies such as Kraken and Sony deploying their own rollups on Superchain.
There are many topics to discuss with Superchain, with aspects as diverse as the size of the ecosystem, the number of applications currently in operation, the growth of on-chain data, and even the evolution of governance.However, this article will focus on the technical aspects of these multifaceted features in particular, delving into issues related to interoperability and finality.
1. overview of Superchain
Before we get down to business, let's review "Superchain" and its underlying technology in detail.
Superchain is a collection of interoperable rollups built on the OP-Stack development framework provided by Optimism.Unlike traditional models that rely on a single blockchain, Superchain aims for multiple roll-up chains to work closely together as if they were one giant chain.This model is designed to combine scalability and interoperability to lay the foundation for a new web3 ecosystem.
1-1. What is OP-Stack?
The core technology of Superchain is OP-Stack, which provides a standardized set of modules for easily building roll-up chains.The framework allows developers to quickly and efficiently create their own chains while maintaining compatibility with the Optimism ecosystem.Projects such as Base (a roll-up chain built by Coinbase), World Chain, and Manta Network have adopted OP-Stack and are working together as a Superchain, albeit as independent roll-ups, to form one large eco-system.
1-2. Purpose of Superchain
The primary goal of Superchain is to increase interoperability.In the traditional blockchain ecosystem, each chain manages its own data and assets independently, and exchanges between chains are done via bridges.In Superchain, multiple roll-up chains share a unified technology platform and operate under unified rules, allowing secure message sharing and asset transfer between different chains.This allows for secure message sharing and asset transfers between different chains.
2. how finality works
2-1What is finality?
Finality is the state of a transaction being "finalized" on the blockchain, making it unalterable.Finality on Ethereum is typically achieved in 12-15 minutes, but can be delayed due to network congestion or other factors.Finality is an important component of the overall reliability and security of the blockchain.
2-2. Finality in a Roll-up Chain
As many of you know, roll-up chains do not perform finality.Ethereum plays that role.The roll-up chain only processes transactions and sends the results to the Ethereum mainnet, entrusting it with the final consensus and data storage.Through this mechanism, the roll-up chain itself does not achieve finality and remains in a "provisionally confirmed" state.
In the Optimism mechanism, after a transaction is provisionally approved, it goes through a verification process called Fault Proof to ensure that there are no irregularities.This verification is subject to a challenge period (usually 7 days), during which time, if any irregularities are detected, the transaction in provisionally confirmed status will be cancelled and reorganized.On the other hand, if no problems are identified during the challenge period, finality is achieved on the Ethereum mainnet and the transaction is officially confirmed.
2-3. What is the problem with asynchronous cross-chain communication?
While the finality of the roll-up chain is not yet finalized, it creates unique challenges in an interoperable ecosystem such as Superchain: Fault Proof reduces reorganization risk, but each roll-up needs time to wait for finality, so crosschain communication will be asynchronous.
What is the problem with this asynchronous nature of Superchain?
On the surface, most cases are designed to be reflected immediately, so users may think there is no problem at first glance.In reality, however, behind the scenes, the data is optimistically matched between Chain A and Chain B, and any discrepancies are reconciled later.This approach does not completely eliminate the risk of data inconsistency between chains due to block reorganization.
For example, in the event of a complex cross-chain transaction or a system failure, multiple roll-up chains may not be exactly consistent with the data at that point in time, and it may take time to correct the state.This is a structural risk that could cause a major failure of the entire Superchain.
In addition, as the number of rollups and use cases within Superchain increases in the future, the complexity and its risks will increase.Against this backdrop, the efficiency of finality and the asynchronous nature of cross-chain communications are important technical issues for Superchain's growth strategy.
3. understanding finality reorganization risks
Up to this point, you have gained an understanding of Ethereum and roll-up finality risk.Let's dig a little deeper here to understand the "reorganization risk" a little better.
3-1. What is the risk of finality reorganization?
Reorganization of finality refers to the phenomenon where a rollup finality fails for some reason in the Ethereum mainnet, and a new block is generated again to replace the previous block, causing inconsistencies in the transactions in the rollup chain.
Specifically, the risk occurs during the following process
Roll-up from the source chain to the Ethereum mainnet: After the transaction is processed in the source roll-up chain, it is combined into a batchThe transaction is processed by the originator rollup chain and then grouped into batches.At regular intervals, batches are rolled up into Ethereum.
Fault Proof (7-day challenge period): Roll-up chains created with Optimism use a roll-up verification method called Fault Proof(The roll-up chain created by OP Stack uses the Fault Proof roll-up verification method.(Roll-up chains created in the OP Stack can also be implemented.) In Fault Proof, once all transactions are inscribed on the main net, there is a challenge period of 7 days after the transaction is inscribed.A challenge period of 7 days is established after the transaction has been inscribed.During the challenge period, suspicious transactions can be denounced and the authenticity of the transaction verified.If the accused transaction is verified and found to be fraudulent, the transaction will be voided and the rollup will be reorganized and finalized.
Consistency breakdown: When a reorganization of rollup data occurs, the transaction finalized on the mainnet becomes inconsistent with the source chain.In this situation, if the source chain shares data with another roll-up chain, for example, and the interoperability becomes more complicated, the possibility of bugs increases accordingly.In the unlikely event that something triggers inaccurate or invalid data for the entire ecosystem, the entire Superchain could derive the impact.
3-2. Interoperability Impact of Superchain's Goal
Superchain aims at interoperability, which is the seamless exchange of assets and data between different roll-up chains.However, finality creates certain risks in achieving this if it is not achieved successfully and reorganized.This challenge is mainly manifested in the cross-chain bridging and messaging passing mechanisms within Superchain.
Cross-chain bridges and asynchronicity
Cross-chain bridges are an important infrastructure for moving data and assets between different blockchains; bridges in Superchain work by conveying transaction data generated by the source chain to the destination chain.This process involves the following steps.
Transaction generation in the source chain: The transaction is processed in the source chain and the result is retrieved by the bridge.This data is based on the state root and block hash of the source chain.
Message Forwarding: The bridge forwards a message from the source chain to the destination chain.This message contains information about transaction results and state changes.
Pending data application in the destination chain: Even though on the surface the account reflects data immediately, behind the scenes, in order to prepare for reorganization risk, data status changes are pending in the destination chain until the source chain transactionis fully finalized (finality achieved), data status changes are pending on the destination chain to guard against reorganization risk.
This mechanism of waiting for data state changes to achieve finality avoids the risk of reorganization in the source chain, but on the other hand, the data is shared asynchronously.
Messaging Passing and Integrity Challenges
Messaging passing is the underlying mechanism for cross-chain bridging and serves to transmit data and instructions between different chains.In this mechanism, a message recorded in the outbox by the source chain is received by the inbox of the destination chain, which processes the transaction accordingly.
However, in consideration of the reorganization risk, the content of the message is not executed until finality is confirmed by the source chain.This hold period, while necessary to guarantee message validity, poses an asynchronous interoperability challenge for Superchain.
Superchain is currently being adopted by many roll-up projects and companies and serves as an important platform for interoperability.In the future, as the number of rollups increases and more advanced use cases emerge, these technical risks may gradually become apparent.
4. improvements being considered
The challenges faced by Superchain have already been recognized throughout the ecosystem, and it appears that discussions on improvement measures are underway.Various technologies have been proposed and are being worked on for concrete implementation to enhance interoperability, reduce reorganization risk, and improve transaction efficiency.This section introduces some of the typical improvement measures.
4-1. Standard Rollup
Standard Rollup is a new methodology designed on the basis of Optimistic Rollup to enhance interoperability and data integrity within Superchain.The standard ensures data sharing and transaction sequencing based on uniform rules across multiple rollup chains.
To address the reorganization risk of the current Optimistic Rollup and the asynchronous nature of cross-chain communications, the verification mechanism has been enhanced with Fault Proof to ensure consistency across the ecosystem in the event of a reorganization.The Standard Rollup is a foundational improvement that will improve the overall reliability and efficiency of Superchain.
(Reference:https://gov.optimism.io/t/season-6-standard-rollup-charter-ratification/8135) 4-2.
4-2.ZK Fault Proof
BNB Chain's proposed "ZK Fault Proof for OP Stack" is an idea to streamline the existing Fault Proof system by utilizing Zero Knowledge Proof (ZKP).The goal is to replace the traditional verification process with ZKP and reduce the challenge period from the current 7 days to about 12 hours.This proposal has the potential to make cross-chain communication faster and more secure by helping to reduce gas costs and the risk of verification interference.
The hurdles to realization are the computational cost of ZKP generation, the increased speed of proof, and the difficulty of designing dedicated circuits (custom circuits).In particular, technologies based on high-performance zkEVMs and other technologies require enormous resources for design and implementation, and integration with the existing Ethereum network is also a challenge.
(Reference:https://gov.optimism.io/t/zk-fault-proof-for-op-stack/8648)
4-3. Proof-of-Execution based on zk-Proof
zk-Proof (zero-knowledge proof) is intended to simplify the process of accurately and quickly proving the status of the source chain and applying the result in the destination chain.This reduces the risk of reorganization.
At present, however, this technology also has the following challenges: zk-Proof generation requires high computational power, which in turn raises the issue of cost.In particular, the more complex the transaction, the more complicated the proof generation, resulting in higher gas costs and network-wide delays.In addition, operating Proof-of-Execution throughout Superchain requires implementation in each Superchain roll-up chain.The cost of this implementation and the challenges of maintaining consistency across the ecosystem remain difficult to resolve.
(Reference:https://4pillars.io/en/articles/superchain-interop-research)
4-4.Shared Validity Sequencing (SVS)
Shared Validity Sequencing (SVS) is also known as "shared sequencing.This enables efficient cross-chain communication while maintaining transaction consistency.However, to realize this mechanism, advanced communication protocols and security measures are required, and no concrete implementation schedule has been determined at this time.We also need to determine how to achieve this efficiently.This requires the cooperation of the entire ecosystem.
(Reference https://www.umbraresearch.xyz/writings/shared-validity-sequencing)
5. summary: future prospects for the superchain ecosystem
For Superchain to grow as a sustainable ecosystem, there are technical challenges such as interoperability asynchrony and finality reorganization risk, but improving on these is key to improving the security and user experience of the Superchain ecosystem.Improvements that leverage Standard Rollup and zero-knowledge proofs have the potential to reduce interoperability asynchronies and process transactions across chains in a more consistent manner.However, these technologies are not yet at a mature stage and continued research and development is essential.
In addition to technical progress, operational and community cooperation is essential for Superchain to grow as a sustainable ecosystem.First, even if the technical requirements are in place, they must be realized under a unified vision across the ecosystem.This means adopting new technologies and sharing a consistent direction in each independent roll-up chain.However, the reality is that the larger the ecosystem, the higher the hurdles to align.
In this regard, it seems to me that there are lessons to be learned from the Cosmos Hub experience: at Cosmos Hub, we have faced many challenges in bringing the entire ecosystem together.Similarly, as Superchain's ecosystem grows in size, a key theme will be how to maintain the uniqueness and overall harmony of each roll-up chain.OP Labs' leadership will be essential to achieving this harmony.We believe that we need to work with each roll-up chain in a unified overall manner while promoting innovation on the technology side.
Ultimately, Superchain's goal is an inclusive ecosystem that combines interoperability and economic sustainability.To achieve this goal, it is essential not only to overcome technical challenges, but also to share a common vision for the entire ecosystem and strive to build a culture and operating structure to make this vision a reality.With independent roll-up chains working together under a unified vision, and technology and community developing together, Superchain should be the key to building a truly sustainable union.
Disclaimer：I carefully examine and write the information that I research, but since it is personally operated and there are many parts with English sources, there may be some paraphrasing or incorrect information. Please understand. Also, there may be introductions of Dapps, NFTs, and tokens in the articles, but there is absolutely no solicitation purpose. Please purchase and use them at your own risk.
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