In this article, we discover what is the node of the sequence, which is an ecological component of the ethereum excitement.
This infrastructure entity is responsible for a series of processes that bring transaction data made on L2 to the main L1, as it acts as a calling point.
The operation and degree of decentralization in the sequence directly affects security, reliability and resisting control over these solutions.
Let’s see everything in detail below.
What is the serial and what is its role in the world of EVM
In the scene of the expansion of ETHEREUM, The sequence device is an entity that requests and performs transactions outside the series, and it collects it outside the series before it is published on Blockchain Layer-1. Its main role is to improve expansion and efficiency of layer 2 solutions, such as Rollups, by reducing gas costs and speeding up the completion of transactions.
Technically is defined as a knot, and the sequence device processes the transactions that have been implemented on the limbs and covered in compressed.packThen he sends this data to Ethereum, where it is officially recorded and added to the initial series responsible for safety.
Depending on the structure of layer 2, the sequence device can be central or uncovered, and it can affect important aspects such as arranging transactions, data availability and control resistance.
in case Optimistic separationLike expression and optimism, the TX serials order and publish them on ETHEREUM on the assumption that they are all valid unless it is competed. in ZK-RollupHowever, such as Starknet and ZKSYNC, the series not only treats transactions, but also generates encrypted encoding evidence on Ethereum. Finally, in Rolub from Manager Write like zkfair and rhino.fi, a hybrid process occurs where data is partially verified.
It is important to emphasize that this number is also used by Blockchains solutions and other expansion, but to avoid confusion, in this article, we will only focus on the EVM world. To know, we point out to this There are components similar to sequence sequences in ecosystems such as the universe, sub -networks of collapse, and Silista.
The functioning of the series in the various Ethereum rollups
Dive is deeper in the various tasks performed by the sequence owners, we see how they run the life cycle that was implemented within a Rollup.
We can collect their workflow in 3 basic steps: Collect and sort transactions, implementation and publishing on Ethereum.
1) Collect and sort transactions
Users send transactions to the sequence device instead of L1 directly, which you orders in a specific block according to the demand strategy. In general, in rollups, we find “”On the basis of auction“The strategy, where the auction is made to determine the implementation order (those who pay more fees have a priority and are requested first).
Other strategies can be from “The first to come first serve“The type, where transactions are accepted and processed in the order they reach.
2) Implementing the state and its account
After determining the arrangement of transactions, the sequence device is implementing it locally, and updating the Rollup status outside the chain.
This implementation is inevitable and follows the rules specified through the smart contract of the contracts on L1, thus ensuring the safety of operations.
3) Production and publication of payments on L1
At this stage, transactions are assembled in batches and sent to L1 ethereum.
SEQUENCER only publishes the basic data (Caldata) of data availability (DA), ensuring that ETHEREUM can always rebuild the situation on the chain. This step guarantees the use of minimal arithmetic to maintain low L2 network fees
Based on the type of rolling, these three steps can vary greatly or less, as shown in the following table.
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| Tipo Di Rollup | Raccolta Dati | escuzione | Publicazione Su L1 |
| Optimistic separation (Irbia, optimism) | The sequence device collects the transactions that users send. | The sequence applies and executes the transactions, then spread it in a batch. | Data is published on the series, and transactions are accepted after the challenge period |
| ZK-Rollup (Starknet, ZKsync) | The sequence device collects transactions and creates a set of data for processing. | The sequence device executes transactions and generates ZK resistance to show authority. | Evidence of encryption ensures the validity of transactions, without the need for a challenge |
| Manager (Starkex) | The serial device collects the transaction data, but it keeps it outside the series. | The serial device carries out transactions outside the chain and updates the situation. | The data is not completely consecutive, which reduces costs but with less safety compared to the rollers on the chain. |
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Central series of the series
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Currently, most series on Ethereum are centralizedSince all Rollups operations have one knot responsible for the L2 and L1 communication management. This composition is necessary in “”Stage 0“Rollups stages, where the concession between decentralization and expansion is necessary to make the entire infrastructure functional and effective in the initial development phase.
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Moving forward with the passage of time, Rollups aims to disassemble its serials, and to provide new solutions to the participation of the knot and the union, and thus move to “”Stage 1And “and”Stage 2“However, in the meantime, it can create excessive centralization of supplies, even for a limited period of time, serious structural problems of the network from the second level concerned.
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First of all, it is entrusted with controlling one knot “offering”One point of failure “: If the series will suffer from an attack, technical failure, or a manipulationThe entire infrastructure can be penetrated, leading to delaying transactions or even service interruption. Moreover, this energy concentration can be easy The risk of censorship of transactionsSince the individual operator will have the ability to exclude or arrange transactions arbitrarily, by applying mev strategies.
Another aspect is related ConfidentThe lack of a distributed health verification mechanism makes it difficult for users to independently verify that transactions have been properly processed. All this undermines the principle of decentralization at the base of Ethereum philosophy.
The centralization of the nodes represents a double -border sword: the practical example of the -2 layer.
The excessive centralization of the sequence is formed as a A double -edged sword, It is able to provide an entire ecosystem literally from collapse, but at the same time he is able to lead to strong arbitrary control of the network.
What happened to Layer-2 Linea in June last year, during the penetration and exploitation of the Velocore protocol, is a clear example of this.
On that occasion, during the cybersecurity on DeX, the team at Consensys (which runs Rollup) decided to do so The production of the mass stopped, “closingHer sequence. By doing this, with the series freezing practically, the Velocare team managed to contain the accident and solve the symbol that it faced. Meanwhile, Consense controls the attacker’s address, making communication with the sequence device impossible (which, as we remember, verifies transactions and sends them to L1).
If the sequence device is not closed, there will be very dangerous economic consequences, with effects not only on Linea, but also on Ethereum.
Crunatrs could have drained more money from weak smart contracts, which led to the exhaustion of the value of assets on the basis of Linea. In addition, the attacker could change the state of the network, making it difficult to discover and repair the problem.
This could have been the repercussions of other DEFi protocols related to Linea, causing many users to suffer references or irreversible losses.
The ethereum community of Velocore Hack led to thinking about An accurate balance between security and decentralization. On the one hand, quick intervention by Consensys is a financial disaster, and to protect users and protocols from significant losses. On the other hand, the closure of the sequence and control device on the attacker’s address raised concerns about the excessive central power that Tabqa 2 operators keeps.
