Questions tagged [blocks]

This tag is for questions dealing with the structure of blocks.

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1answer
15 views

When MetaMask removes the Cancel button for a transaction?

When I start a transaction, MetaMask shows it with Cancel button. When does this Cancel button disappear? Maybe after one confirmation? After N (what is N?) confirmations?
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1answer
15 views

Uniquely identifying and lexicographically sorting transactions

Is event.blockNumber + '-' + event.logIndex unique for an Ethereum transaction (that is no two different transactions having it the same)? If not, is event.blockNumber + '-' + event.logIndex + event....
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1answer
23 views

Solo block verification

If I have one block from bitcoin blockchain. I can check that block is valid without having the previous blocks. (solo block verification) Imagine I have one block from Ethereum blokchain. Can I check ...
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0answers
15 views

is “newBlockHeaders” in web3 emits a legit block?

I'm using web3.eth.subscribe('newBlockHeaders') to track transaction I sent to the blockchain. My question is that is the block emitted from "newBlockHeaders" legit or in other words, the block has ...
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0answers
16 views

Block number as part of header rationale

It seems to me that block number is something that can be derived correctly by a node locally (from the parent block relationship). What was the purpose of including it in block header -> making it a ...
0
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1answer
21 views

Blockhash Minus-256 Problem [duplicate]

What is meant by Blockhash Minus-256 Problem? I am reading an article at: Bad Randomness It talks about Blockhash Minus-256 problem but does not explain much about it. As a result I can’t ...
0
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1answer
42 views

Blockhash: Register the block number

I am reading the following article from a website: bad randomness In the context of Blockhash the author says: For instance, a good protocol (formulating a random trial as a “bet”) is the following: ...
2
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1answer
30 views

What is meant by on-chain randomness? What is the difference between on-chain and off-chain operations in the context of randomness?

I want to understand on-chain and off-chain operations in the context of randomness. Kindly provide me an example so that its clear to me. I got one post here: What are offchain and onchain ...
6
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1answer
614 views

How to retrieve ERC20 from a hacked address monitored by a bot?

Check it out: https://discordapp.com/channels/554623348622098432/633092550407749652/714325610050355260 The address that was hacked: https://etherscan.io/address/...
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1answer
35 views

Spending funds before the block is mined

Suppose I have an application that receives funds from users and instantly moves them into an associated cold storage account. If one of our nodes detects a transaction broadcast to one of our ...
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1answer
28 views

web3.eth.getBlock isn't triggered

Basically, i want get the callback result of first method to get each index value in pass it to the second method to scan this value, in this case is an ethereum transaction to get the input value. ...
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0answers
17 views

What’s the transaction ordering inside a block? [duplicate]

The game I found a game where each gambler needs to pay 0.02 ᴇᴛʜ to register a secret before the game before the games switch to status==reveal each day. Then, during the status==reveal period no ...
2
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0answers
34 views

When is a “shard block” cross-linked into a “finalized beacon block”?

In Ethereum 2.0, a shard block for being finalized needs to be linked into a finalized beacon block. Under which conditions a "shard block" cross-linked into a "finalized beacon block"? Having 2/3 of ...
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1answer
35 views

What's the difference between a Slot and a Block?

I'm running a private beacon chain with the Lighthouse client with some local validators: Mar 23 10:35:08.281 INFO Block from local validator block_slot: 13009, block_root: 0x2bab…25a6, ...
2
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1answer
47 views

What if a malicious validator denies to sign a new block in a shard committee in Ethereum 2.0?

In Ethereum 2.0 (Sharding Blockchain), a new block requires to be signed by all the validators as members of a committee, where blockchain has been sharded in smaller parts for supporting parallel ...
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1answer
38 views

What is the block number of the first block mined in a private blockchain network deployed on say Quorum?

I am working on POCs on Azure Blockchain Service. While working on quickstarts, I observed that while deploying my 'Hello Blockchain!' smart contract, the block number of the block mined was 34136. ...
4
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1answer
69 views

How transactions are selected by the miners?

The deployment of transaction executions is bounded by the block gas limit that changes dynamically. If a block fits only one transaction, then the gas limit per transaction is, in theory, the same as ...
3
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0answers
37 views

Blocks can't contain more than 81 transactions

I'm building a private blockchain with Parity clients. For performance testing, I'm submitting many identical transactions. One of the nodes has a GPU miner attached. There are 2 issues I cannot ...
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1answer
24 views

What is the max number of Blocks which can be created in Quorum

I have nodes running from past few days, with almost 4100+ transactions successfully completed. When i try to interact with the contracts again to add/modify details it shows error Error when ...
3
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2answers
73 views

How does Ethereum prevents a node from mining a block with tempered transaction?

My question is rather simple, and I found this question in the Bitcoin StackExchange that somehow relates to mine, although, for the Bitcoin Blockchain, which I'm not sure if Ethereum solves the ...
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2answers
42 views

Can anybody here help me in understanding how transactions and block is getting verified [closed]

Please help me in understanding how transactions are getting verified and also how blocks are getting verified before appending it to the canonical chain.
0
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1answer
28 views

Integrity of old blocks in the blockchain

I am learning Ethereum using Geth, and I am testing PoA-Clique networks. Now I have a conceptual doubt about old blocks integrity. Suppose I have a private blockchain network of only one miner node ...
0
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1answer
46 views

Multiple GasLimits on my Private Ethereum network?

I am wondering if it is available to make multiple gas limit block in one of my private networks. The multiple gas limits blocks in a private network means that size 10, 100, 1000 and so on, those are ...
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0answers
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What happens if in the genesis file, I put something different than 0(0x0) for the “number” property?

From what I have understood, the number property from the genesis file represents the block number (to match block structure). So, logically, it should be 0x0 because the genesis file is the first ...
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1answer
69 views

Private Clique network, where can I get block sealer and block reward?

Private blockchain PoA validation algorithm Using geth attach MY-GETH-CLIENT, I want to check the sealer of a block as well as its reward. Using eth.getBlock(BLOCK-NUMBER), the miner field is ...
0
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1answer
33 views

Is Ethereum block header a list?

Decoding a RLP encoded block using Eth specifications do we get header as list? But as per format i.e., [[blockHeader,transactionList,uncleList],totalDifficulty], blockHeader should have been string. ...
2
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1answer
41 views

4.3.1. Transaction Receipt-Yellow Paper

I am trying to understand the following function which appears in section 4.3.1 of the Ethereum Yellow Paper: The function description state it "prepares" a transaction receipt, does it mean that the ...
0
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1answer
35 views

Writing string to separate block in Ethereum

Is it possible to take input of a string from client side and using smart contract write that string data to a new block inside the Ethereum blockchain mainet or any testnet? Basically take in ...
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1answer
35 views

Are there block rewards for ETH2 validators during Phase0

ETH2 is rolling out in multiple phases. The first phase (typically called phase 0) is the minimal beacon chain. Does this chain already include block rewards? If not, what's the incentive to stake ETH ...
2
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1answer
80 views

How to calculate average time it takes for a transaction to be added to Ethereum blockchain?

In the following article (LINK) we read: "despite the fact that at the time of this writing a new block is produced approximately every 10–20 seconds the average time it actually takes for a ...
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1answer
46 views

Web3: can last block be replaced?

I'm using web3py's getBlock function to get the latest block. I am right now caching the latest 50 blocks so that I reduce the amount of workload in my geth node, and to improve overall speed in my ...
0
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1answer
111 views

How do Miner choose transactions for a block?

i am wondering how a Miner chooses the transactions, he want to mine inside a block. For example, a Miner has got the Transactions T1 and T2 at the moment he starts a new mining work. This Miner is ...
2
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1answer
47 views

Can the block number be set back in ganache?

I know about tools like ganache-time-traveler that let you advance the block number. But is it possible to go back to a lower value?
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1answer
24 views

In ethereum network how data structured and is every data stored, is public?

Let's say, 3 companies are using ethereum network. Company A Company B Company C Company A put some data, block01 and block02. So ethereum network looks like, Genesis Block -> block01 -> block02 ...
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2answers
33 views

Does a transaction that consumes the block gas limit take an entire block by itself?

Does a transaction that requires the entire block gas limit to be executed (currently ~8M) take the entire block by itself? And if that's true, will that transaction take longer to get confirmed than ...
0
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1answer
27 views

Can I rely on certain oracle to know the precise and reliable timestamp?

I am learning the security impact of smart contract on system properties like block.timestamp and block.number. I understood that block.timestamp can be controlled by the miner to certain degree and ...
1
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1answer
39 views

“The bigger the block size, the greater the computational power needed to mine a block” Does this make sense?

I was going through one of the papers and the authors in the paper mentioned this statement. I am not able to find the correlation as such. I do understand that Larger blocks may propagate slower ...
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0answers
21 views

Mining pool assign blocks

I've been researching mining pools to figure out how they assign work to miners. I understand that pool would get a job from the blockchain they only has a header, dag, difficulity, probably block ...
3
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2answers
1k views

Avoid using “now”

I am using "now" to save the block timestamp details. But there is a warning to avoid its usage. If we need to avoid it what is the best alternative to it.
1
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1answer
45 views

Are transactions to EOA included in a block guaranteed to be successful?

Regardless of the source of the transaction (externally owned address / smart contract) and the data included within the transaction, if the destination is an EOA and the transaction was included in a ...
2
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1answer
47 views

Are transactions with zero data included within a block guaranteed to be successful?

I know there are transaction receipts to verify that a transaction included in a block was executed successfully and funds were actually transferred. But can receipt verification be skipped if I'm ...
0
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1answer
12 views

How to get blocks from which an adress has taken coins&

I need to undeerstand how to find out from which blocks come coins that are currently stored at somee adress.Will be pleased to hear any suggestions.
3
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2answers
242 views

What is the difference between account nonce and block nonce?

Block and accounts both use a value called "nonce" but they seem to represent something very different. For account I understand that the nonce is an integer quantity indicating the number of ...
4
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1answer
123 views

Timestamp in Ethereum

I have a smart contract where the user inputs temperature readings, I'd like to add a time stamp to relate those reading with a current time of submission. I understand that in Ethereum we only have ...
0
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1answer
62 views

How to calculate average gas price of several blocks?

I want to calculate average gas price of several blocks (in Gwei), however I don't see how a field on blocks for gasPrice. Do I have to calculate it by grabbing the gasPrice of each transaction in ...
0
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1answer
49 views

Is there any library to estimate timestamp of future block?

I am in need of a library that estimates a date or some sort of timestamp when fed with a future block number (on mainnet or any major testnet). For instance, https://etherscan.io/block/countdown/...
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0answers
21 views

Parity synced at not existing block 4839212

I have problem with parity, cant get synchronization in archive mode to end, anything, changing arguments, max-, min-, snapshot-peers, parity verisions do not help. I have blockchain in archive mode ...
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0answers
56 views

Is latest block returned by eth.getBlockNumber fully processed

According to web3 docs, web3.eth.getBlockNumber returns the number of the most recent block. My question is simple. Is it safe to assume block's transactions and events are already in the node or ...
1
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1answer
40 views

Fetching block template from node

The most famous opensource pool uses eth_getBlockByNumber method with parameter "pending" to get block template and generate jobs from it. But now, in parity, I found that this parameter is deprecated ...
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3answers
388 views

Increase block number on Ganache

How can we increase block.number on Ganache for testing purpose ? If not possible do you know an alternative like passing X fake transactions to artificially increase block.number. Or if we have to ...

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