Questions tagged [blocks]
This tag is for questions dealing with the structure of blocks.
193
questions
0
votes
1answer
11 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
vote
1answer
17 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 ...
0
votes
0answers
10 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 ...
2
votes
2answers
71 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
vote
1answer
27 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
votes
1answer
32 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
votes
1answer
10 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.
2
votes
2answers
58 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
votes
1answer
40 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
votes
1answer
26 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
votes
1answer
18 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/...
0
votes
0answers
13 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 ...
0
votes
0answers
25 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
vote
1answer
25 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 ...
0
votes
0answers
43 views
What is the m_seal fields in the block header used for?
Can someone please explain what these
extra fields in the block header are and what are they for?
Edit:
Oh, I just understood myself -- mixHash and nonse are stored here. But why is this data ...
1
vote
3answers
122 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 ...
3
votes
1answer
118 views
When is a new block created?
I am currently reading an interesting book about solidity, and I'm reading about block creation. This gives a good overview:
The book mentions that the maximum size of a block is determined by the ...
1
vote
1answer
16 views
Can I get the timestamp for a transaction added to mempool?
Can I get the time stamp on when a transaction was added to the mempool and when it was successfully added to a block?
Is there an API to do this?
6
votes
1answer
1k views
My friend sent me a screenshot of a transaction hash, but when I search for it I find divergent data. What happened?
This is the transaction hash:
0x90e923ee01d9dfeb95ee176819eeec67d247fc6cb009c8cdc4d8ae1939e5ecc6
And this is the screenshot my friend sent me:
If you check the hash in Etherscan, some informations ...
1
vote
1answer
41 views
Is there a smart contract recording all block hashes on in the ethereum blockchain, as they come in?
I'm wondering whether anyone has already made a contract and corresponding off-chain service which, once every 30 minutes or so, triggers the contract to record all the block hashes which have gone by ...
2
votes
1answer
28 views
Known cases of miners withholding blocks when used as randomness?
There are some applications that use the blockhash as a source of randomness, often with a payout similar to a lottery. I've heard of attacks where it would be more profitable for a miner to withhold ...
1
vote
1answer
160 views
How to get the value of the transaction?
I am using web3.py but I need help to know the value of the transaction sent.
I know that the information is stored in the input but how do I parse the string. I know nothing about ABI.
Here is the ...
0
votes
1answer
13 views
changing source of random number based on reward?
Would this be an acceptable way to produce a random number dependent on the reward?
Say if the reward is high enough to entice a miner to manipulate the block then the contract will utilize oraclize.
...
0
votes
2answers
205 views
Modify number of confirmations
By default there are 24 confirmations but I am running a testnet with just 3 miners and I would like to change this number bucause it makes not sense to have 24. I have been checking ...
0
votes
0answers
11 views
How to read the data from block?
In my smart contract, I am inserting plain text message.
I can also update the message.
After updating, if I want to see the previous message, is it possible?
Can I see all the data in etherscan.io?...
1
vote
0answers
34 views
How to mine a Empty Block or reject transaction?
How Can a miner can mine a empty block,reject honest transactions to be added into block ; does it mean we could tweak the miner client , if yes could someone tell how it is done and what are the ...
1
vote
1answer
135 views
How can i implement deadlines in smartContract?
Suppose I am running a gallery and ask participants to submit there paintings before a specific date. After passing that date participant should not be able to submit their entry. How can I implement ...
1
vote
1answer
19 views
Make sure I don't jump any blocks
I'm making a simple program to track transactions in and out of an address, I have a function that gets the latest block and then I run it consecutively.
When I run the function sometimes the block ...
2
votes
0answers
56 views
How to read block propagation delay from ethstats.net?
I am wondering what is the average (or mdeian) time it takes to propagate a block in the Ethereum blockchain?
I found ethstats.net provides a cummlative graph for block block propagation but do not ...
1
vote
1answer
22 views
How to change all the ethereum blocks from C drive to D drive — question about the answer
I'm new here and have no idea if this is the right way to respond. So I duplicated the question a have a question about:
I've done the things written in the answer on the original question and I ...
0
votes
1answer
25 views
Is there multiple chains of block in ethereum network?
Since blockchain is a chain of blocks,
In ethereum,
1. is there only one chain of blocks
2. are there multiple chains of blocks.
1
vote
0answers
43 views
What actually a block contains, is the data inside it a virtual or physical entity?
My understanding of a block in blockchain is that it is a data structure that contains information like Block Size, Block Header, Transaction Counter and then Transactions. Deeper in the Block Header ...
1
vote
1answer
189 views
How State variable are stored and updated?
The Smart contract and the state variables are stored in the blockchain, let us say during deployment of a smart contract the state variable and smart contracts are stored in the block 1, and in ...
1
vote
1answer
49 views
Looking for an Ethereum sniffer
I have been looking for a sniffer similar to Bitcoin P2P Network Sniffer (https://github.com/sebicas/bitcoin-sniffer) which could allow me to connect to Ethereum nodes and listen to blocks and ...
1
vote
1answer
36 views
Getting the last synced block is 0
I am trying to get last synced block but it always 0.
So I have run
geth --syncmode fast -cache 4096 --rpc
Here is a logs
INFO [12-19|09:47:50.058] Imported new state entries count=...
1
vote
2answers
72 views
Who generates the mathematical problem for miners?
In POW miners solve an problem for successfully mining a block, who provide the question to the miners ?, does all miners work on same problem ?, and how the miners verify the answer ?, if the problem ...
0
votes
1answer
46 views
how to get the last incoming transaction before date
I need to get the incoming transaction before the date currently i use
https://web3api.io/api/v1/addresses/0xaD4b04Df17f2d35F81771Fa124dBD94E33587F4c/transactions?to=...
1
vote
0answers
52 views
Get blocks between dates
I am trying to get the block between dates . for that i use web3.js . per day average block is 6172 so if i need previous day block i use below code
fromBlock: (await web3.eth.getBlockNumber()) - ...
0
votes
2answers
89 views
can only change header's extra data to mine a new block? [closed]
Fix 'nonce' and 'mixDigest', only change 'extra' to mine a new block.
1
vote
1answer
36 views
How will Proof of Stake affect blockhash generation
When (and if) Ethereum switches to proof of stake, how will the hash of blocks (most likely) be set?
1
vote
0answers
43 views
Ethereum Blocksci parser tool
I need a blocksci parser for ethereum.
I am using https://github.com/citp/BlockSci for bitcoin .
Is any similar blocksci parsing tool for ethereum?.
1
vote
2answers
44 views
0 txn in mined block [duplicate]
How is it possible for a block to be mined with 0 txn?
https://etherscan.io/block/6739171
That's an easy way to get 3 ETH block rewards.
1
vote
1answer
21 views
Is state read from the current or previous block for external function calls?
Given that a computer must execute in a sequence, I assume the VM is also doing so before deciding the final block state. Let's say my contract calls an external function from another contract that ...
8
votes
2answers
217 views
Possible error in white paper validation algorithm?
If we take the block validation algorithm described in the
white paper (Section Blockchain and Mining), it states at point 6:
Let TX be the block's transaction list, with n transactions. For all i ...
5
votes
1answer
27 views
Will block numbers be sequential on a sharded blockchain
When Ethereum shards (assuming it does) will the block numbers across the multiple shards be unique? I doubt it (I don't think the shards can have sequential block numbers and be independent of the ...
1
vote
1answer
26 views
Does a non-miner node validate both single transactions and an entire block?
My understanding is that an originating node broadcasts a transaction to its neighbours, who all validate the transaction to ensure (a) the signature is valid and (b) the state change is valid, before ...
2
votes
1answer
60 views
Is there any point in adding msg.sender to an event?
I am asked to provide the value of msg.sender as part of an event emitted in a function.
It is something like:
contract MyContract {
event MyEvent(address indexed sender, uint256 input, uint256 ...
0
votes
2answers
168 views
How to get multiple blocks timestamps with a single JSON RPC call?
Is there a way to get data similar to the ones provided by web3.eth.getBlock(blockNumber) but with multiple blocks at once?
The goal is to get the timestamps for 100 blocks in a row without ...
1
vote
0answers
130 views
Same Block Received More Than Once With Same Block Parameters
Use Case:
I am implementing a deposit system where I will get a block as it is mined and parse transactions to check for a deposit of Ether or a specific token. Getting the same block twice will ...
1
vote
1answer
611 views
How can I retrieve the transaction hash / block hash of a contract that has already been deployed?
If you use Web3.py to deploy a Solidity contract to the blockchain, you can retrieve a transaction hash, like this:
tx_hash = w3.eth.sendRawTransaction(signed.rawTransaction)
Once you have that ...
