As standalone layer-2 chain development kits become more and more popular, today we take a look at some of the well-known ones and compare whether they make a difference. Please note!
First, we will take the time to understand the two representatives of Optimistic Rollups, Optimism and Arbitrum. However, please note that in their chain development tools, these two networks still retain the possibility of zero-knowledge improvements according to the needs of the application project.
Optimism OP stack
The first toolkit that already has a sample product and some third-party projects uses it is OP Stack. Basically, this is a toolkit to realize the vision of a "super chain", that is, a network of many different OP chains, by transmitting data on the chain and relying on Ethereum to provide security and authenticity.
OP Stack Application Project
Announced projects that will apply the OP Stack toolkit include:
BASE - Layer-2 backed and developed by Coinbase
opBNB - Layer-2 of the BNB chain
Zora - NFT Marketplace
Pika Protocol plans to build Layer-3 "Pika Chain" on top of OP Stack in 2024
These projects use the OP Stack toolkit to build their respective Layer-2 or Layer-3 chains to achieve higher scalability and throughput, and ensure security and authenticity while maintaining interoperability with Ethereum.
In addition, several other projects have also announced technical support for the toolkit. Specifically, Celestia said it will develop the Modular DA data layer for the OP Stack.
To-do issues
In the documentation of OP Mainnet, some unresolved issues and future improvement requirements are also mentioned. These backlog issues include:
Withdrawals from Layer-2 to Layer-1 depend on a set of validators (testing units).
Cross-chain transactions can be slow because they must wait for the verification process to complete.
Complex, highly synchronous cross-chain transactions (such as flash loans) will be difficult to execute between chains.
Data verification cannot be easily scaled because the hyperchain must be collated and rely on Layer-1.
There is currently no toolkit that supports DApps integrated on multiple hyperchains.
The wallet platform currently does not support connecting to multiple hyperchain networks at the same time.
Orbit decision
Another project taking the Optimistic Rollups approach is Arbitrum, which has released details about the Arbitrum Orbit toolkit.
The difference between OP Stack and Arbitrum Orbit (which can be considered temporary as it may change in the future) lies in the number of layers that both ecosystems pursue in their development vision. According to the published project document details, by OP Chain, it can be understood that these chains are chains that develop next to (or around) the current Optimism. Arbitrum has opened up both Layer-2 and Layer-3 development directions (networks built on Layer-2).
These toolkits provide developers with the framework and tools to build high-performance, scalable, and secure Layer-2 and Layer-3 chains. They all aim to improve the usability and user experience of the blockchain by reducing on-chain load and transaction costs. However, these toolkits are still under development and may require further improvements and optimizations to address some backlog issues and limitations.
Unlike OP Stack, Superchain can be deployed freely (without permission), while
Layer-2 requires approval from Arbitrum DAO, while Layer-3 can be deployed arbitrarily.
Orbit Chain can customize parameters such as security, governance, and especially the token used to pay transaction fees. The custom details of choosing the token as transaction fee is the next difference, as OP Stack does not explicitly mention this information.
Recent Development Updates
Projects that have officially announced that they will use Orbit include:
Syndr (derivatives exchange) announced that it will develop the Syndr chain by the end of 2023.
Additionally, according to founder Steven Goldfeder, there are currently 33 Orbit chains being developed on Devnet.
Currently, Arbitrum Orbit has just entered the Devnet deployment stage. Here are the instructions this toolkit sends to projects in the community.
Additionally, Arbitrum plans to integrate the Stylus upgrade into its toolkit by the end of 2023. This is an upgrade that allows developers to participate in building contracts using other languages such as Rust.
Backlog issues
Since the model is very similar to OP Stack, I would like to summarize some of the issues mentioned above, including: the speed of interoperability between Orbit chains (InterOps function has been implemented), and relying on security (data interaction) on Layer-1.
Another potential issue concerns the tokens used to pay for transaction fees, a detail that could cause contention in the community.
However, one positive aspect is that Arbitrum Nitro is now believed to have integrated fraud proof, so the reliance on Sequencer-Attestor will be reduced to some extent.
Next, we will look at the toolkits developed for ZK-Rollups. Due to differences in approach (e.g. proofs of validity — fraud proofs) and to avoid confusion, I thought it would be more appropriate to separate this group into a separate section.
zkSync的ZK Stack
On the evening of June 26, zkSync Era and Matter Labs announced details related to their ZK Stack toolkit. If teams want to deploy on the current zkSync platform, ZK Stack will also open up two development possibilities, namely Layer-2 and Layer-3.
Regarding the connection phase, there are also similarities with other solutions. Specifically, interactions between branch chains will be supported through Hyperbridge.
backlog problem
Similar to the previous two solutions, Hyperchain will also be limited by the degree of decentralization and the number of Sequencers operating the network.
Unlike OP Stack and Arbitrum Orbit, which have issues with the interaction and liquidity linking between branch chains, zkSync Era integrates a bridge solution called zkPorter. This solution is expected to solve the liquidity fragmentation problem faced by most high-level blockchains.
Starknet Slush
The next representative is Slush, developed by Starknet. The name may not be completely similar to the previous representatives. This is because in addition to supporting the construction of independent chains, Slush will fork the Tendermint toolkit, create a new virtual machine environment, and connect this virtual machine system to ABCI's system. In simple terms, Slush will support a deeper level of infrastructure than other solutions.
This difference stems from the fact that StarkNet does not follow the direction of pure EVM compatibility (Solidity is not supported by default), so technical details need to be adjusted (in particular, the development of the Cairo programming language needs to be supported).
However, from the perspective of development vision, Layer-2 and Layer-3 are also the ultimate goals of this toolkit.
Latest development updates
Since the Starknet infrastructure is not yet fully complete and 100% Regenesis implemented, it can be considered that this Slush toolkit is still in its infancy. A notable integration of Slush is that the toolkit has opened a source code branch to support Solidity development of zkSync Era if the project requires it.
Additionally, the future roadmap for the toolkit includes:
Building a Tendermint light client that supports the Cairo language
Deploy Cairo on Tendermint and ABCI systems
Send the block to the SHARP validator (a block validation mechanism developed by Starknet specifically for Cairo)
According to the project documentation, at the time of writing it will take approximately 3 months to complete these milestones and implement the Layer-3 vision.
Backlog issues
Starknet is still not completely finished in building a Layer-2 platform. Therefore, it will take more time for the network to scale Cairo to multiple projects. From that point on, Layer-3 can begin to be deployed.
The current transaction processing speed of the mainnet is not impressive. Therefore, if we fail to focus on opening up Layer-2, the pressure on the mainnet will increase day by day when multiple branch chains are deployed.
polygonal super network
Basically, the system design and goals of this toolkit are similar to the one named above. The difference is that the central platform of this toolkit is Polygon PoS, and following the announcement on June 20, 2021, it has now been migrated to the zkEVM Validium mechanism.
This means that unlike the aforementioned Rollup form, Validium is more efficient in terms of cost and transaction speed. But in return, there are certain risks in terms of security, because the authentication data is stored off-chain, unlike the aforementioned solution that puts the entire data verification process on-chain.
Recent Development Updates
It can be said that Supernets is not the focus of Polygon's development at present, because the project has too many sub-projects to pay attention to, such as Polygon ZKEVM and even the current PoS flagship network.
Perhaps the most notable update to the toolkit is that German telecom giant Telekom will be involved in operating a validator node for the Supernets development network.
Backlog issues
As mentioned above, Validium raises some concerns about the transparency and security of storing authentication data off-chain.
The problem of liquidity fragmentation will require Polygon to come up with many new solutions in the future, because this is an ecosystem that has developed many different branches and networks.
Summarize
So we've looked at some of the current private chain development kits built by Layer-2. Obviously, this is a trend that many projects are following, but when it comes to implementation, it needs to be very flexible to avoid unnecessary complexity for the entire blockchain ecosystem.
