Interpretation of the five major stages of Ethereum in the future, what is the final form of Ethereum

introduction

"The Merge", that is, the conversion of Ethereum to a proof-of-stake network, is planned to be completed on the mainnet by the end of September this year. This upgrade aims to systematically improve the accessibility of the blockchain and transition Ethereum from a Bitcoin-style proof-of-work consensus mechanism to a proof-of-stake system. Ethereum's roadmap from performing sharding to being Rollup-centric is a critical step in scaling the blockchain for the next billion users. As noted in our previous article, Exploring Modular Blockchains, data availability and sharding in modular architectures allow blockchains to scale throughput without sacrificing decentralization. At the same time, the article conducts in-depth discussions on data availability, Rollup, and failure/validity proofs, laying the foundation for further understanding of the background and goals of the merger. This article will provide an in-depth analysis of the technical details of the merger, Ethereum’s new roadmap, and what the change means for users and developers.

Source: @ptrwtts

Rollup-centric roadmap

Originally, the plan for Ethereum 2.0 (the term has now been dropped) was to achieve scalability by dividing the mainnet into 64 shards, each with independent miners/validators. Users will then send transactions to specific shards based on congestion, utilization, and throughput. Due to the continuous development of Rollup and the complexity of performing sharding, the original scalability roadmap centered on performing sharding is no longer applicable, so people began to adopt data sharding. In the view of the Ethereum team, Rollup will become a key element of Ethereum expansion. They plan to make the upgraded Ethereum a strong settlement and data availability layer, and let Rollup gain security from it.

Source: ETH2 Book

The Beacon Chain

Contrary to the common view, the purpose of the merger is not to reduce transaction costs, but to transform Ethereum into an infrastructure layer for Rollup, and the construction of the beacon chain is the first key step to achieve this goal. Ethereum will change from the previous "proof of work" system to the "proof of stake" system, and in this system, pledgers must provide collateral in order to produce blocks, so as to prevent any dishonest behavior. After the consensus system is transferred to proof of stake, the verification committee will be introduced as a primitive, thereby strengthening the network consensus and paving the way for the formation of an efficient intra-protocol data availability layer. The beacon chain is responsible for coordinating stakers and does not process or execute transactions like Ethereum does today. More specifically, the merger is actually merging Ethereum's old execution layer with the new consensus engine provided by the beacon chain, converting the existing algorithm that utilizes miners under the proof-of-work system into a coordinated network of validators under the proof-of-stake system. At the same time, this transformation also laid the foundation for sharding: in the past, under the proof-of-work system, miners' work was not recorded, so they could stop working and leave the network at will; under the proof-of-stake system, the beacon chain will All approved block producers are registered and can coordinate and parallelize validator votes.

Source: ETH2 Book

The formation of the validator committee is an important innovation of the beacon chain. They are randomly assigned by the beacon chain and are responsible for voting on blocks and forming consensus. The committee's combined vote is called a witness message, allowing people to easily verify the state of the beacon chain by checking the committee's vote, which minimizes block size and data compared to verification by a single validator increase. At the same time, the attestation message also strengthens the consensus, because in this mode, creating a fork will require the participation of a large number of validators. In addition, validators will be replaced regularly to prevent malicious validators from colluding to launch attacks.

Source: Flashbots

Consensus and MEV (The Splurge)

After the merger, Ethereum will have a proposer-builder separation for the consensus layer. Vitalik believes that all blockchains should eventually have centralized block production and decentralized block verification. Since the fragmented Ethereum block data is very dense, block production must be centralized due to high requirements for data availability. At the same time, we must also set up a decentralized set of validators to validate blocks and perform data availability sampling.

The builder role builds blocks of Ethereum execution payloads with user transactions and submits them along with bids for acceptance by proposers (a randomly selected subset of the validator set). Once the proposer accepts the payload, they sign the block and propagate it through the network. This structure eliminates the possibility of validators catching up, since the payload sent to the proposer is stripped of the transaction content. In an efficient market, the introduction of the block space market also incentivizes builders to participate in MEV bidding, allowing decentralized validators to obtain most of the MEV rewards. Compared with simulating Ethereum, this setting can effectively prevent miners from destabilizing the consensus and reduce the generation of harmful MEV.

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Danksharding (The Surge)

While the separation of proposers and builders was originally designed to counteract MEV's harmful externalities and centralization forces, the Ethereum core team realized that it could also serve data sharding.

Danksharding is named after the core contributor Dankrad Feist. Its main innovation is a merged fee market that replaces the original shard with a fixed number of different blocks and proposers. All transactions and data in a specific time will be picked by the proposer . Behind this proposer is a randomly generated committee of validators that samples the availability of blockchain data. In this way, the data availability of light clients can be maintained in a decentralized manner, subject to the large amount of data in the merged block, which is simply not possible in a single point of verification. Since consensus nodes are also performing data availability sampling, this model is able to unify the settlement layer, consensus layer, and data availability layer.

A unified settlement and data availability layer opens new doors for rollups utilizing proof-of-validity: ZK Rollups are now able to make synchronous calls with the execution layer on Ethereum. This enhances new L2 primitives such as distributed liquidity and fractal scaling, laying the foundation for building the next generation of innovative Dapps on ZK Rollup.

Proto-danksharding

While danksharding is good for Ethereum going forward, it won't play its full role immediately after the merger. Proto-danksharding (EIP-4844) is the original version of darksharding, which is planned to be released before the full implementation of darksharding. This proposal creates a primitive called a Blob-carrying transaction. As the name implies, this type of transaction is one that carries a data payload called a blob. Blobs will serve as the data standard for Ethereum after sharding: they are bundled with KZG polynomial commitments ( KZG polynomial commitments ), and due to decoupling from EVM execution, Blobs are also a more efficient format than calldata. At present, Rollup is still using call data to transfer transaction data back to Ethereum, resulting in high gas costs. In the future of sharding, Rollup will use Blobs to save users the gas costs associated with EVM execution. At the same time, the goal of proto-danksharding is to provide developers with this cutting-edge data format, and at the same time temporarily reduce the data cost of their Rollup by introducing a separate format and charging market for their data to be sharded. Although proto-danksharding itself does not actually implement sharding, it provides a standard for the data format after sharding, which is also the first step in building an efficient native data availability layer.

History and Status (The Verge & The Purge)

At the same time, we also need to consider the state of Ethereum and its storage. Since validators must complete their tasks on consumer hardware products, the increased state can affect decentralization. The Proto-danksharding blob was detached from the EVM execution layer and deleted after about a month. Additionally, EIP-4444 can cause clients to stop serving historical data at the peer-to-peer layer after about a year. Regardless, we had to enforce some type of mandatory history expiration at the protocol layer, since sharding adds about 40TB of historical blob data per year. The blockchain state needs to be stored on RAM or SSD, however, the historical storage, which is the data that Ethereum has reached consensus, can be stored on cheap HDD. Since the history store operates on an honest minority (1-of-N) trust model, we do not need to store history data on nodes performing real-time consensus at all. The Danksharding specification ensures that validators store and guarantee the availability of data they have reached consensus for months. Afterwards, these truncated historical data will be stored by third parties, such as application-specific protocols, BitTorrent, Portal networks, block explorers, individual enthusiasts, or indexing protocols.

Source: Consensys

Stateless Ethereum is another goal on the roadmap. Block producers will use witness information, which is a proof consisting of relevant data required to execute the transactions in the block. Clients can then use this proof to verify that executing the block's resulting state root requires that they only execute a portion of the affected state, rather than the entire state. In this design, the scale and usability of the proof are two core issues: the first issue can be solved by converting Ethereum's state data structure from the protocol-level specification ). According to Vitalik, in scaling Ethereum, we need to rely on centralized block producers with specialized hardware while retaining decentralized validation.

Summarize

Danksharding inherits the security of Ethereum and also puts forward higher requirements for Rollup. After tightly coupling data availability with the consensus and settlement layers, we can upgrade the underlying infrastructure so that Rollup can leverage native data availability solutions and remove the security assumptions of validity and voluntary. This lays the groundwork for Enshrined Rollups to be built to remove risk in governance and smart contracts in the future. At the same time, Enshrined Rollup, which uses SNARKs to make synchronous calls within the protocol, has also become a key design for future blockchain expansion. The advantage of Rollup in the protocol is that it will eliminate the daily fixed gas cost of the smart contract Rollup and is measured by the number of blocks; and, because the calculation is decoupled from the consensus, the verifier no longer needs to re-execute the transaction to verify the block; in addition , the state difference can be guaranteed by the validity proof, and the stateless client no longer needs to download the witness proof. With these advantages, settlement latency will be improved, synchronization and validator bandwidth will be improved, and the security of cross-chain bridges will be more assured. The Ethereum Foundation is currently working to implement this design into Ethereum's roadmap, and plans to upgrade the EVM to a SNARK-compatible Enshrined Rollup.

In previous posts, we discussed the benefits of modular off-chain architectures, and solutions for data availability, settlement, and execution that third-party protocols are developing. The main goal of the Ethereum roadmap is to minimize trust assumptions and provide scalability within the protocol through native solutions. Ethereum's base layer hosts an entire ecosystem of decentralized applications that promises to fundamentally change the way we think about identity, storage, search, reputation, and privacy in the digital age. As we upgrade Ethereum to a base layer, we also optimize this application layer, allowing users and developers to scale more use cases on a secure, robust global infrastructure. For Ethereum, its vision is to build a digital future for the entire world. At the same time, it will continue to adhere to the principle of trusted neutrality, and continue to develop Ethereum's network effects, decentralization, and security, thereby consolidating its position in the future decentralized network. In this way, the merger is the first step Ethereum has taken to realize this vision.