Questions tagged [block]
The components of the blockchain and a data structure that collects transactions.
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Do I have to download all blocks to see my bitcoin using bitcoin-qt?
I saw a youtube video about bitcoin wallet and he said you can't see your bitcoin or send or receive until the bitcoin-qt download all the blocks.
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JSON-RPC getwork data field
I recently tried playing around with the getwork command for JSON-RPC and I'm trying to understand what I got out of it. According to the API Call List wiki entry, the "data" field should contain the ...
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Correct Citation Format for a Bitcoin Transaction
When writing an academic style paper where specific bitcoin transactions are used as examples, is there a standard format to "cite" a bitcoin transaction?
If not, what do you think an appropriate ...
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How can I view the Blockchain locally on my machine?
I'd like to view the blockchain on my Windows 7 machine. Right now I'm looking under roaming/Bitcoin/blocks, and trying to open blk00000.dat . I can't read any of it though, it seems the text is ...
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Can I replace a single corrupted block?
I'm running Bitcoin Core on Linux and it seems I have a single corrupted block file which is causing problems. It's taken me 2 weeks to download 75% of the blockchain, so I'd like to replace the ...
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Can Bitcoin Days Destroyed be a better resolution mechanism for competing blocks?
I've been looking at selfish mining and empty blocks. In all cases, the selfish miner profits by keeping block solutions private until their value to his own pool is maximized, rather than releasing ...
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No Account number or Address in listtransactions for generated blocks
I am in the need (for my app development) of having more information printed with the "listtransactions" of the bitcoind daemon.
For blocks generated it shows the account as "" and no bitcoin address ...
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Which block has the lowest hash? [duplicate]
Which block has the lowest hash currently? Is there a website that allows to sort blocks by hash?
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What is the "confirmation" field in a block?
What is the importance of the "confirmation" field in a block?
How many confirmations are required to accept a block in a blockchain?
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Is there a well defined last block?
It's fairly well known when the last bitcoin will be mined, but is there a well defined last block?
By that I mean, is there a block height H after which Bitcoin Core nodes will refuse to accept any ...
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where is difficulty target inserted?
All miners at any time must have a consensus on the "difficulty target" to be able to achieve the correct nonce (as answer of proof-of-work).
Assume that the target has been updated (it means that ...
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Download blocks in blk00000.dat format from a specific period
For study purposes, I would like to download blocks from a specific period, i.e. January 2017 - June 2017, in blk.dat format (blk00000.dat, blk*.dat).
I downloaded blockchain.core but it makes me ...
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Can a Bitcoin block be less than 1mb?
Can a Bitcoin block be less than 1mb?
To my understanding, a miner receives broadcasts. However, if not enough transactions come in, then would it just prematurely hash the block?
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Verifying Bitcoin ownership
Suppose Alice has 30 bitcoins from David. Now Alice wants to transfer amount 20 bitcoins to Bob.
Now, Alice creates a transaction with Bob's bitcoin address.
To prove authenticity and integrity, ...
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Default behaviour when network partitions/pruned network
From people oposed to SegWit I have heard about the argument, that after SegWit activation, nodes may chose to drop/prune all Witnesses. From my understanding, this may not be much different from ...
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What is the variable in a block that holds hash of found PoW?
Can anyone please tell me, which variable holds the hash of the solution of block's PoW in broadcasted block?
I know that a block consists of (I am pretty sure I am forgetting some variables here):
...
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Does the block reward get halved every 4 years regardless of hardware advancements?
Is the invention of a faster computer (let's say a quantum computer) or the lack of advancements in computing power (let's say it takes a decade to make any progress greater than incremental increases ...
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Is pre-mining of a future block possible?
Is it possible to pre-mine next block when everyone is mining current block?
Let's say, if we need 1T hash power to mine (solo / pool) a block in 1 hour, then is it possible to run 1G hash miner for ...
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Does local blockchain database (blkXXXXX.dat) contain abandoned forks forever?
When my node realizes that the given block needs to be abandoned - does it leave it in the database or replace the block with a valid one? And if "invalid" block remains: is it somehow ...
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Which cryptocurrency has the smallest block time?
What is the lowest block time of any cryptocurrency? I don't mean the time of an individual block, but the target time per block.
What is the shortest reasonable block interval?
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How does the network apply credit for created blocks?
First post. I must say in advance thanks to everyone for all the great conversation and help and software so far. It's really helped me get familiar with bitcoins and bitcoin mining.
I have a ...
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What would happen if miners refused halving
In may 2020 the supply of bitcoin per block is supposed to be reduced by half https://www.bitcoinblockhalf.com/
What if after this phase the first miner or more than 51% of them decide to keep the ...
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What is the difference between Root Hash and Block Hash?
I was reading about how Bitcoin works from Satoshi's original paper. I had a query while going through the 7th paragraph. What is the difference between Root Hash and Block Hash? Isn't the block hash ...
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Blocked transaction wallet on my phone
Ok I have a wallet on my phone that I put bitcoins in on monday, They have been blocked now for a week. How do I unblock them and the wallet I am using I can get it on my mac. Its called bitwallet by ...
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How does a share help in the discovery of a new block?
https://en.bitcoin.it/wiki/Pooled_mining:
A share is awarded by the mining pool to the clients who present a valid proof of work of the same type as the proof of work that is used for creating blocks,...
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Bitcoin Difficulty granularity
Difficulty adjusts by very granular percentages to target for 10 minutes blocks. But adding another zero at the end of the chain of zeroes from the header hash requirement for a valid block would ...
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Is the ordering of blocks in the rev*.dat files same as the blk*.dat files?
I understand that blk*.dat files save the blocks in the order it gets them from it's peers. Is the rev*.dat files in the same order as the blk*.dat files?
For example, would the 400th magicbyte in ...
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Modifying data in existing blocks
NOTE: I am a Bitcoin newbie. Please excuse (and correct) any wrong terminology in this post.
Can the transaction data in an earlier block be edited? Of course, it would break the verification of the ...
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Would an increased blocksize lower the stress of the stress tests?
I see that there are about 9000 unconfirmed transactions right now and that five of the last six blocks are under 1/2 Mb and 15 blocks in a row under 750 Kb. This suggests to me that larger block ...
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How Does Network Difficulty Relate to the Odds of Finding a Block?
Right now the network difficulty for mining is 40640955016.576. And, according to blockexplorer.com, the current odds of finding a block for any given hash is 0....
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Where are block announce times recorded?
Times at which a block is initially announced to the network aren't recorded in the block. Does bitcoind record at least the local time each block was seen the first time? Does anyone have any ...
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Chronological list of transaction ids
Is there a way to get a list of the latest transactions IDs? I know I can watch incoming transaction almost live on http://blockchain.info, but is there a way to download the last 10.000 transaction ...
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Is it possible to retrieve input addresses and input values of bitcoin transactions from raw blk.dat files?
I'm developing a script that processes blk.dat files from bitcoin core. So far, I am able to retrieve the following attributes for transaction inputs:
"vin",
"index",
"...
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Sender, nodes or miners? Who validates transactions?
I have been reading a lot about the validation of transactions. I understand the actual method in which a transaction is composed (inputs and outputs). However, I don't know what happens with that ...
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How segwit blocks are seen by segwit and non-segwit nodes?
Let's say a miner mines a block.
In this block some transactions will be non-segwit and some will be segwit?
The block contains two parts:
The part with transactions
The segregated part with ...
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What is the mechanism by which the 'system' adjusts the difficulty of finding blocks so one is found on average every 10 minutes? [duplicate]
Here we read:
In the Bitcoin network, only blocks with certain hashes get accepted and included in the official list. The criteria for which blocks "count" is that their hash has to be ...
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Do all block have to be verified every time a new block is broadcasted?
I did a presentation for my office and during the presentation I was asked a question that I was not prepared for. It's a more technical question from my perspective, but someone here might already ...
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Transaction broadcasts and block synchronization
In the original publication about bitcoin, in section 5 it states that
If two nodes broadcast different versions of the next block
simultaneously , some nodes may receive one or the other first. ...
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How to handle incomplete blocks when reading blk*.dat files?
I'm trying to write a parser for blk*.dat files from scratch. Right now, I can read blocks, extract the header fields and calculate the correct block hash based on the header fields.
I just tried to ...
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Is Bitcoin network an Asynchronous network or a synchronous network?
Conventional BFT protocols work on weak timing assumptions, and if a faulty primary does not respond or forward a client's request a view change message is initiated by the backup nodes. Therefore, if ...
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Would this scheme allow faster verification of transactions? (Multiple parallel block chains)
One issue with one block chain is that it needs to be globally synchronized. One way to elevate this would be to use multiblock chains.
Namely, we can imagine that there are N block chains, working ...
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Why is CheckBlock called twice when processing a new block?
Once the Bitcoin node receives a message with a new block, it calls the ProcessNewBlock function:
else if (strCommand == "block" && !fImporting && !fReindex) // Ignore blocks ...
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What is the purpose of Merkle Tree in blocks?
The leaves of the Merkle Tree has the hash of the transactions. How are transactions stored in the block? What is the purpose of Merkle Tree.
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How could the dogecoin increase the limit of money supply?
As far as I know, Dogecoin will only have 100,000,000,000 coins in total. But how can the supply of coins remain uncapped? How could it produce unlimited dogecoins? Is there any specific skill to make ...
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Understanding POW and transactions
If I understand correctly, when calculating a proof of work, the entire header is being used in a sha256 function.
Now, whenever a new transaction is added to a pre-mined block, the header completely ...
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Random numbers using blockchain
How are the block hashes generated?
Are they trully 100% random (generated by hardware) or is it pseudo-random (generated by software)?
Can i rely on it or any other blockchain data to make a 100% ...
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Are blocks containing non-standard transactions relayed through the network or not as in the case of non-standard transactions?
When a node receives a non-standard transaction (for example, it has more than one OP_return output or has some of the non-standard outputs), it will not be relayed further through the network, ...
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Relation between transaction data and transaction id
What is the relationship between transaction data and transaction id (which is used at mempool to generate Merkle root)?
Note : when we query the getblock with verbosity 2, we get raw block in json ...
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Is it possible to increase the prune size and get bitcoind to pull previous blocks?
for example, currently its:
"size_on_disk": 32084546902,
"pruned": true,
"pruneheight": 650668,
"automatic_pruning": true,
"prune_target_size&...
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How does the structure of a segwit block differ from a non-segwit block?
Is there any difference in the structure of a segwit block in comparison to a traditional non-segwit block? A diagram would be helpful if possible.
