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Are there any examples of rollups with multiple types of blocks?

I'm curious if there are any examples of rollups that have more than one type of blocks? Example of what kind of differences there could be between blocks: Blocks of type Foo have 30M gas limit, ...
Paul Razvan Berg's user avatar
0 votes
1 answer
7 views

Why does the first block of the epoch include all the L2 deposits that happened in the L1 block?

From Optimism docs: Transactions get to the sequencer in two ways: Transactions submitted on L1 (called deposits) are included in the chain in the appropriate L2 block. Every L2 block is identified ...
Paul Razvan Berg's user avatar
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0 answers
11 views

How can a rollup use multiple Data Availability layers?

From Optimism's docs: The Data Availability Layer defines where the raw inputs to an OP Stack based chain are published. An OP Stack chain can use one or more Data Availability module to source its ...
Paul Razvan Berg's user avatar
0 votes
0 answers
8 views

Why is only the first call frame aliased on Optimism?

Because addresses can be impersonated cross-chain, rollups have to alias addresses when L1 to L2 transactions are performed. From Optimism's docs: CALLER msg.sender If the transaction is an L1 ⇒ L2 ...
Paul Razvan Berg's user avatar
2 votes
0 answers
16 views

Gas cost of simple ETH transfers on Arbitrum

Historically, Arbitrum enforced a minimum of 400k gas for transactions. Here's an example of a simple ETH transfer I performed in July 2023, which cost ~411k gas: https://arbiscan.io/tx/...
Paul Razvan Berg's user avatar
3 votes
1 answer
20 views

How are the base fee and the blob base fee trustlessly relayed from Ethereum to Optimism?

I was reading Optimism's docs on Transaction Fees, and I noticed these statements: The L1 Data Fee is most heavily influenced by the Ethereum base fee that is continuously and trustlessly relayed ...
Paul Razvan Berg's user avatar
2 votes
1 answer
62 views
+50

Can a rollup be decentralized if it is run by a single validator?

This is a question about the decentralization status of Ethereum rollups. Based on what I can see on L2Beat, most rollups are currently at Stage 0, meaning they have two more stages to go before they ...
Paul Razvan Berg's user avatar
1 vote
1 answer
70 views

Do all EVM chains use the same minimum transaction gas of 21000?

Do all EVM chain use 21,000 gas as a minimum transaction gas for simple ETH payments? Optimism seems to do so. How about the other EVM chains?
Paul Razvan Berg's user avatar
0 votes
1 answer
16 views

Are all L2s rollups?

It seems when people refer to L2s, they are always referring to rollups. So, is the term interchangeable?
Patrick Collins's user avatar
1 vote
2 answers
184 views

How is rollup data verified with blobs?

Historically, rollups post compressed batches of transactions to the L1 which can be verified because all the data is stored in calldata. However, as of EIP-4844 which was included in the Dencun ...
Patrick Collins's user avatar
1 vote
1 answer
20 views

Why a zk-rollup should provide data availability given it can use zkp to prove correctness?

The whole idea behind zkp is to prove correctness of the result of a computation without actually disclosing the inputs that you might want to keep secret. So why in the context of zk-rollups it is so ...
Davide C's user avatar
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1 vote
0 answers
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How do people solve NFT cross-chain when developing on your own rollup?

This is a question about developing a game using its own side-chain. In this case, the NFTs would be minted on the side chain. Now the players can trade NFTs with each other but some of them might ...
Justin Zhang's user avatar
0 votes
1 answer
138 views

Comparison of NEAR and Celestia Data Aavailability Approaches? [closed]

Recently NEAR has come up with a Data Availiabity approach which they claim to be far more superior to a lot of existing techniques. Celestia DA leverages 2D Erasure Coding based Data Availability ...
Gokul Alex's user avatar
3 votes
1 answer
67 views

ZK rollups: How to check whether specific transaction is included in batch?

ZK rollups don’t store transaction on L1. They just need the Zk proof the check correctness of state transition and additionally state diff so users would be able to reconstruct the rollup state in ...
Felix's user avatar
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2 votes
1 answer
51 views

ZK rollups: How is state diff data in batches checked for correctness?

Situation: ZK rollups don’t need to publish any transaction data on L1 to ensure correct state transition because the zk proof takes care of correct state transition without knowing (i.e. zk) anything ...
Felix's user avatar
  • 53
1 vote
1 answer
42 views

Are rollups run by a single sequencer centralized from a censorship point of view?

In other words, can sequencers censor txs on rollups such as Arbitrum or Optimism?
Paul Razvan Berg's user avatar
1 vote
1 answer
57 views

In optimistic roll-ups, can a validator post a valid block that builds on an old-but-invalid block which was not challenged?

In optimistic roll-ups, blocks (aggregated transactions) are published on the Ethereum main net. The main net functions as a security layer for the roll-up in the sense that it leverages the security ...
Kianoush Arshi's user avatar
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0 answers
16 views

Optimistic rollups and simple transactions

My understanding is that in an optimistic rollup, all data from users authorizing a transaction is stored on L1. The computation itself corresponding to that transaction is executed on L2. For simple ...
user1936752's user avatar
2 votes
1 answer
37 views

Why does rollup data in Ethereum have to be on chain?

In this blog, it is said Rollups move computation (and state storage) off-chain, but keep some data per transaction on-chain. The fact that data is on-chain is key (note: putting data "on IPFS&...
user1936752's user avatar
1 vote
0 answers
69 views

What happens with Chainlink price feed when L2 sequencer is down?

What exactly happens with chainlink price feeds when an L2 sequencer is down? I know that during this moment transactions can be submitted only through L1 rollup contract and that some users can be ...
urataps's user avatar
  • 91
2 votes
2 answers
55 views

Rollup Operators Colluding and Withholding Data?

For Rollups like Optimism and Arbitrum, what happens if the sequencer colludes with a proposer so: The sequencer withholds data The proposer publishes an invalid state update (so he can drain the L1 ...
Rodrigo Herrera Itie's user avatar
0 votes
0 answers
21 views

What exactly is Fuel blockchain?

They describe themselves as execution layer for the modular blockchain, but what exactly does this mean? If they are the execution layer, where are the other functionality/layer? Consensus layer, data ...
Finlay Weber's user avatar
0 votes
1 answer
107 views

Are there any Ethereum L2 projects that built based on the Parity Substrate framework?

Substrate is a powerful framework that makes it easy to build a blockchain. I am more familiar with the substrate development than the Layer2. and am curious about why there are no Ethereum Layer2 ...
boundless-forest's user avatar
1 vote
0 answers
39 views

why does optimism need to derivation from L1 but zk-rollup scheme like polygon zkevm not?

recently I am reading the optimism docs and the spec named derivation confuse me. I haven't found it in any docs of zk-rollup projects like zksync, Polygon, or zkevm.
meta's user avatar
  • 11
1 vote
0 answers
56 views

Who pays for the L1 gas costs of ZK-rollups?

I have deployed the same smart contract on both the Goerli Testnet and the Polygon zkEVM Testnet. When I execute the same interaction, it costs the same amount of gas on both networks (as expected), ...
Abel's user avatar
  • 73
1 vote
1 answer
187 views

What does it mean by "rollups sends transactions on mainnet"?

While trying to understand what rollups are, I read rollups sends transactions to mainnet in a batch. I don't understand why and practically what does it do. To better understand it, I came up with a ...
Stav Alfi's user avatar
  • 216
2 votes
0 answers
17 views

Difference between zk-rollups and nocust-zkp

What is the fundamental difference between ZK-Rollup and Nocust-ZKP? Does the data availability problem still persist in Nocust-ZKP? After going through zk-sync, I felt it might be fundamentally ...
Subhra Mazumdar's user avatar
1 vote
0 answers
58 views

what data of zk rollup blockchain are sent to l1?

I am not clear about how data flow from l2 to l1 in zk rollups. does someone knows what data of l2 are sended to l1?
aakash4dev's user avatar
0 votes
1 answer
123 views

smart contract rollup vs sovereign rollups?

I read here about smart contract and sovereign rollups: https://celestia.org/learn/sovereign-rollups/an-introduction/. I am curious to know what are the pros, cons and differences between both types ...
aakash4dev's user avatar
1 vote
1 answer
30 views

calldata usage, difference between the method calling function with calldata

I recently studied optimism, and found that appendSequencerBatch() of CanonicalTransactionChain contract called with calldata. I assumed that this function was called using 0x(functionSelector)+(data.....
gun bos's user avatar
  • 25
2 votes
0 answers
42 views

What is "Data availability problem" in Plasma?

What differentiates Rollup from Plasma is that it solves Plasma’s huge problem — data availability Can someone please describe the "data availability" problem in Plasma? Ok, in Plasma the ...
YodaDefi's user avatar
1 vote
0 answers
82 views

Rollups vs Plasma

This question is related to my another question - Plasma - "If owner does not care about their asset, then an "invalid" outcome may result"? Here https://vitalik.ca/general/2021/01/...
YodaDefi's user avatar
0 votes
1 answer
29 views

Plasma - "If owner does not care about their asset, then an "invalid" outcome may result"?

From Vitalik's article "An Incomplete Guide to Rollups" (https://vitalik.ca/general/2021/01/05/rollup.html): Additionally, Plasma and channels share a key weakness in common: the game ...
YodaDefi's user avatar
0 votes
1 answer
233 views

circom error in zk-rollup circuit: circom error: circuit too big for this power of tau ceremony. 6600*2 > 2**12

while making zk rollup circuit of merkle, i got this error. code for .circom: pragma circom 2.0.3; include "modules/mimicsponge.circom"; // ref: https://github.com/4undRaiser/...
aakash4dev's user avatar
0 votes
1 answer
39 views

bn.inherits is not a function in snarkjs

i am going through this https://github.com/iden3/snarkjs to make zk-rollup via .circom and snarkJS, when i tried to run index.html code it didn't work as per it should. and give error bn.inherits is ...
aakash4dev's user avatar
1 vote
0 answers
23 views

how polygon zk hermez send data from l2 rollup chain to circom circuits?

I'm trying to make rollup, wanna know how rollup works, and specially about one of the good rollup chain polygon hermez.
aakash4dev's user avatar
1 vote
0 answers
148 views

what is the best way to compress/decompress data within a solidity smart contract?

I'm working on a l2 optimistic rollup academic project (thesis), where the sequencer would submit the compressed txs as calldata. At a dispute (aka a different post-state), a verifier would challenge ...
seraleo's user avatar
  • 11
2 votes
1 answer
66 views

Why optimistic rollup chains can take a week, while ZK don't?

Optimistic and ZK rollups, both submit data to Ethereum or similar chain, but why do optimistic rollups take longer time then zk rollups? What's the core difference that causes this time difference?
aakash4dev's user avatar
1 vote
1 answer
24 views

In rollups, does only layer 1<->2 cross chain transfer data is submitted to main chains, or all transactions data of rollup chain?

rollup chains batch the transactions data of its blocks/transactions, and submit it to mainnet(layer 2 e.g. ethereum ). But i doubt if rollup chain submit all data of all transactions in batch form, ...
aakash4dev's user avatar
1 vote
0 answers
51 views

how to make rollup sequencer decentralized?

I know the logic to make a centralised sequencer for a blockchain rollup ( layer 2 solution ) , but i have no idea on how to make the sequencer decetralised. so that no one central authority will get ...
aakash4dev's user avatar
3 votes
2 answers
521 views

How layer 2 blockchain communicate with layer 1 blockchain? where does that communication part is hosted?

I understood what is layer 2 via various blogs, videos and this page: https://ethereum.org/en/layer-2/ But I wanna know: how the layer 2 blockchains communicate with layer 1 blockchains? I guess a ...
aakash4dev's user avatar
1 vote
0 answers
40 views

Arbitrum: Mapping L2 blocks to L1 batches using RPCs

I'm looking for a way to programmatically map L2 blocks to their corresponding rollup batches in L1 using RPCs. Is there a way to do this, and if so, what would be the best approach? Any help or ...
Lucas Pecina's user avatar
0 votes
2 answers
409 views

How do layer-2 bridges and protocols earn revenue?

Everytime I've used a bridge like Polygon and Aztec, all they charge are gas fee transactions to make the transfers and lock-up conversions between layer 1 and layer 2. Bridges therefore are nothing ...
user610620's user avatar
  • 1,528
1 vote
1 answer
44 views

How can privacy roll-ups like Aztec make my transfer cheaper?

Aztec or zk.money, a Layer-2 roll-up, claims to make transactions not only private but also cheaper. If I send 1 eth on L1 mainnet, all I pay is one gas txn to send it. If I instead use Aztec's ...
user610620's user avatar
  • 1,528
2 votes
2 answers
182 views

Will Layer-2s and zk roll-ups become redundant once Eth 2.0 sharding and scaling arrives?

Millions of VC funding dollars are going into Layer-2 solutions like Optimism, Arbitrum and Polygon to allow users to side-step mainnet Layer-1 and process transactions at a thousandth of the cost and ...
user610620's user avatar
  • 1,528
0 votes
0 answers
323 views

Why does Chainlink VRFv2 not support L2 rollup chain like arbitrum or optimism?

All the popular L2 rollup chains are not listed in the supported networks per doc: https://docs.chain.link/vrf/v2/direct-funding/supported-networks/. Meanwhile, Aribitrum and Optimism do have ...
yl35's user avatar
  • 11
4 votes
2 answers
433 views

How verify transaction data in zkrollups?

The stateroot transition is verified by witness (pre- and post- state root) and proof, but validators also should verify the transaction data which is proposed by operators. How can verify the ...
amanec's user avatar
  • 41
1 vote
2 answers
667 views

Can I roll multiple transactions into one?

I wonder whether it is possible to roll multiple transactions into one transaction and post it on the chain, similar behavior to L2 chains. I will have a smart contract where there might be a high ...
Ahmet Yazıcı's user avatar
4 votes
2 answers
60 views

Is there ever going to be some kind of parallelism in Ethereum or any L2?

Suppose I have a long array of values: x = [1, 2, 3, ..., N] # shape [N, ] array and a function def f(x): return x ** 2 then I'd do something like (similar to python's multiprocessing) with ...
H. Arponen's user avatar
3 votes
2 answers
720 views

Finality of Optimistic Rollups

In the documentation for optimism (which is transparent about being somewhat incomplete at this experimental stage in their development), it is stated that "It's important to note that a ...
Paul's user avatar
  • 67