The most important technical event in the "chain circle" recently is the launch of the Ethereum expansion network Arbitrum, which is considered to be the first universal Rollup expansion solution to go online on the mainnet. On June 5, Uniswap V3 passed the proposal and was successfully deployed to the Arbitrum network. The Layer 2 Rollup expansion solution once again came under the spotlight.
Why does Ethereum need to expand? What is Ethereum Layer 2? What is Rollup?
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Calculate off-chain, save on-chain
If you have initiated any transaction on the Ethereum mainnet, the most intuitive feeling should be "expensive (handling fee)" and "slow".
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The average gas fee trend of Ethereum in the past 3 years has risen rapidly in the past two years
And in order to prevent the influence of malicious contracts (such as infinite loop contracts), Ethereum has set up a gas fee mechanism, which limits the upper limit of gas for a single block and the amount of gas that needs to be consumed for each calculation step.
The gas fee is the "handling fee" that users need to pay to participate in the operation on the chain. It motivates miners to process transactions and maintain the network. The miners who dig the block can get the total gas fee for the transactions in the block.
However, with the sharp increase in the transaction volume of Ethereum, the network has become extremely congested, and the price of ETH for gas fees has also increased, resulting in the need to pay tens or even hundreds of dollars for an ordinary transaction.
In order to solve the "expensive and slow" problem, how to expand Ethereum has always been one of the clear development trends in the blockchain industry.
The current expansion methods are divided into off-chain expansion and on-chain expansion. Off-chain expansion is also called Layer 2 (Layer 2) expansion. Its essence is to move operations that should be processed on the chain to off-chain After the calculation is completed, the result is transferred to the chain for storage, thereby improving the working performance of the entire chain. Its process logic is abstracted as shown in the figure below.
That is, by putting the specific calculations on Layer 2 to complete, and then periodically sending the data back to Layer 1, and at the same time verifying and saving it, this greatly reduces the Gas fee for direct transactions on Layer 1. In a simple metaphor, it is like building elevated roads, flyovers, and developing underground passages outside the road to divert congested traffic.
Compared with on-chain sharding expansion, off-chain Layer 2 is currently considered to be the best solution for Ethereum to solve throughput congestion, and it will not change the blockchain protocol itself.
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Rollup plan big PK
Among the above 5 solutions, the most popular ones are side chains and Rollup.
First of all, the Sidechain sidechain can process transactions through a completely independent consensus mechanism, and the data and status are not synchronized with Ethereum. It can be said that the public chains of major exchanges such as BSC and HECO are all sidechains of Ethereum. Although the users on these public chains are very active, the biggest risk is the security of the side chain itself. Once the side chain fails, the assets are easily lost.
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The article "Rollups Incomplete Summary Guide" written by V God pointed out the power of Rollup
Rollup, as the name suggests, is to "roll up" a lot of information. It can summarize the transaction information (status) on the side chain, compress and package the transaction information to generate a hash, and then send it to Ethereum for final confirmation, and only Ethereum can finally confirm the "truth". It just moves the complicated calculations off the chain, freeing up more space on the chain, and even if the data off the chain is destroyed, assets can still be withdrawn.
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OR or ZK?
The Rollup mechanism is currently considered to be the most promising expansion method, while the state channel and Plasma schemes have been rejected by Vitalik.
In the two mainstream Rollup schemes, the core issue is how to verify the authenticity of the transactions in the transaction compression package.
Optimistic Rollup and ZK Rollup use different thinking logics. The former optimistically believes in the authenticity of the transaction, while the latter pessimistically does not believe it. Therefore, generating a zero-knowledge proof comes from proving innocence.
The following table introduces the process, advantages and disadvantages of the two solutions, please click to enlarge:
Among these solutions, the ultimate winner who can occupy most of the market has not yet been determined, but information security and sufficient decentralization are the core expansion requirements.
Vitalik himself also said recently: "At present, Rollup does not have a big challenge, but there are many small challenges. These 100 small problems need to be solved in order to improve the overall performance and user experience."
Blue Fox Notes analyzed: "Layer 2 track: short-term OP (Optimistic Rollup), long-term ZK (ZK Rollup)". ZK has great advantages in terms of efficiency and security based on withdrawing funds. With the adoption of more DeFi projects, the interoperability of ZK Rollup on the second layer can finally be realized.
Some analysts also pointed out that the EVM-compatible Layer 2 solution that can be launched first will have a greater first-mover advantage, increase the transaction rate while reducing handling fees, and the DeFi market may also usher in a reshuffle.
How are the various projects of the Layer 2 Rollup solution including Arbitrum, zkSync, Loopring, and StarkWare performing? What are the specific problems now? Remember to pay attention to the Wootrade public account, we will introduce it to you in the next science popularization.
