Questions tagged [block]

This tag should be used for questions related to Bitcoin blocks

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3
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1answer
639 views

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 ...
1
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1answer
36 views

What would happen if I publish a modified version of an earlier block? Would it be rejected immediately by peer nodes?

I am reading the book "Mastering Bitcoin" and have finished reading Chapter 2 and 10, but I still don't find the answer. Suppose the current main chain has 5 blocks: B0 <- B1 <- B2 <- B3 &...
5
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2answers
4k views

The role of timestamp

In Satoshi’s original paper, it is written that “we need timestamp to prevent double-spending”. However, I think timestamp is unnecessary, because every block has a previous block hash and merkle ...
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0answers
251 views

Estimated number of hashes

This is not a duplicate of previous, similar questions I've read on StackExchange, since none of those questions, nor the answers, go into the difficulty theory, as espoused on the Bitcoin Wiki. ...
2
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1answer
379 views

Fixing “Block not found on disk” rpc error

I have a full node with txindex enabled that I've been trying to use for an electrum server. However, whether I use ElectrumX or Electrs, I hit the same error on initial indexing of "Block not found ...
3
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2answers
365 views

Energy to confirm one block?

What is the minimum energy (or CPU operations) required for someone to confirm one block on their own, to launch a double-spend attack? How can I calculate this from the current difficulty or ...
1
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0answers
21 views

What needs to be done inorder to change difficulty?

I'm trying for a while to reduce difficulty of main network to do some experiments on transactions and maybe simulate some possible attacks.I came up to change nBits field in chainparams.cpp but it ...
0
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1answer
54 views

Why the block's order in blockxxxxx.dat is different from blockchain.info

I parsed the block00000.dat using python code: class BlockFile: def __init__(self, block_filename): self.block_filename = block_filename self.blockchain = open(block_filename, 'rb', ...
22
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2answers
4k views

What are the arguments for and against the increase of the block size limit?

Can someone give a quick point by point list, what arguments the proponents and opponents of increased blocksize have for their case?
2
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1answer
284 views

How come Merkle tree is more efficient when tree branches are not stored in blockchain?

Suppose we have 8 transactions in a block X as follows and we know every node's hash value of the whole Merkle tree (that is, including intermediary nodes such as 45). Then if someone claims ...
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1answer
30 views

Is there any python lib could be used to analysis the local block data?

Just downloaded all the block files to local and want to try some analysis on the transaction data in the block. is there any python library can be used to do the analysis?
2
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2answers
141 views

When are blocks validated?

Are blocks validated just before they are stored to memory, upon receipt from an RPC submit call, or at some other time? Can you point to the place in code where this validation process begins? Is ...
3
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2answers
685 views

How does “headers first” affect BLKxxxx.dat structure?

Assuming a full node running Bitcoincore v0.10 (with txindex=1), how exactly does the new "headers first" functionality affect the structure of the blockchain data? (Specifically, the blkxxxx.dat data,...
0
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2answers
82 views

Why most of pubkeys in the first batch of blocks in blk00000.dat are different

For example: the pubkey in the first 3 coinbase's output are 04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f ...
0
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1answer
21 views

Mining when there is no transaction [duplicate]

what happens when there is noone doing transactions and miners mine the blocks? Can they mine empty blocks? And how it works when there won't be any hash in empty block or there is a hash? Thank you
0
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1answer
26 views

Number of transactions in block

why sometimes block has 16 transactions and sometimes over 2000? I checked it on https://blockexplorer.com/blocks. Thank you
0
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1answer
98 views

In Litecoin every single block is mined every 2.5 minutes, double spending?

In Bitcoin it takes roughly 10 minutes for every block to be mined. In Litecoin it takes 2,5 minutes. 2.5 minutes in Litecoin mean that transactions can be confirmed faster. In Bitcoin these 10 ...
0
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1answer
42 views

Who set the rules for validating a block in blockchain?

Who set the rules for validating a block in blockchain? The rules can be set the creator of the blockchain network. There might be some rules on the application that uses the blockchain network. Is ...
1
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1answer
59 views

While attempting to fetch a particular block my node just gets disconnected by peers?

A system at an office has its testnet node stuck at a particular block. The logs report "requesting block" over and over again for the same block and after each one reports "socket recv error" and ...
2
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1answer
54 views

What would be the implications of limiting Bitcoin transactions to fifty inputs?

One of the issues of increasing the blocksize is the possibility of creating attackblocks which would take significantly longer to parse than the common block. The mechanism to do so is by creating a ...
1
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1answer
17 views

Diffrent transactions in different block sync problem

Consider that miner A and B both try to solve its block, A's block has transactions (T1,T2), B's block has transactions (T1,T3). A solved its block then synced the block to B. Does B will discard its ...
1
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1answer
81 views

Detecting stale blocks with ZeroMQ

I'am writing an application which receives information about new tx and blocks via ZeroMQ. There is a chance that I will receive notifs about blocks which will later on become stale blocks. Is there a ...
0
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2answers
42 views

Bitcoin.org developer reference outdated?

i just can't understand if bitcoin.org developer reference is outdated or not. for example here (https://bitcoin.org/en/developer-reference#raw-transaction-format) we can see: "As of Bitcoin Core 0.9....
0
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1answer
66 views

Why different coins have different number of confirmations?

Does it have to do with the block difficulty? What factors impact the number of confirmations that is considered to be safe in a bloc
2
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2answers
76 views

Blockchain validation process is linear?

I've read at a few places that the nodes validate transactions in a linear fashion, i.e. after node A validates, then node B, etc. (which is also the reason, as claimed by many, why blockchain suffers ...
0
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0answers
55 views

Bitcoin transaction scripts : does ScriptSig or ScriptPubkey run first? [duplicate]

I'm confused as to the order regarding which script is run. For examples sake: say I want to spend 1 Bitcoin which was given to me by Alice in a single transaction of value 1 Bitcoin. I understand ...
0
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2answers
624 views

How similar is Blockchain (as a data structure) to double linked list?

I came across this definition of Blockchain from Oleg Andreev , who is the protocol architect of @chain - It felt like double linked list to me.
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2answers
320 views

Bitcoin New Block Event Trigger

I want to know when a new block is discovered, I am watching debug.log to see if it has changed, I know there is a new block if the line contains "UpdateTip: new best". Is there a better way to do ...
0
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1answer
259 views

How to get Coinbase Text for newly found block

Websites like blockchain.info and btc.com give Relayed By information to find who found the block. I can see coinbase text in the website https://coin.dance/blocks. Is it possible to get that ...
0
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1answer
52 views

who actually amasses or builds the blocks … and how do they get passed to miners?

The question is not about the block being included on the block chain, but who actually creates a block? Like what is the process here. Can someone walk me through this? I do know that blocks are ...
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1answer
331 views

How to add Bitcoins to my wallet

I am new at this and I was given a bitcoin from a miner, how do I know what it is worth and how do I put it in my wallet?
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0answers
29 views

How are transactions hashed together to form a Merkle Root? [duplicate]

In block #59,500 there are 2 transactions Transaction 1. 6653ad77d695752cff9fe63bbb5702a53807be534c537251d53de06aac5ca093 and Transaction 2. ...
0
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2answers
77 views

Block number + bitcoin address -> Find transactions with bitcoind?

If I have a block number and a bitcoin address -> Can I list all transactions for this address with an bitcoind command? Or mutliple commands?
1
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1answer
83 views

Serialized Block doesn't have all the fields of a Block

bitcoin-cli getblock 000000000003b9c88b8a4bf0bac7059913381bba300cdfddffc54a3d8c6e8105 false This command will give block related data in the form of Hex. This Serialized data doesn't contain certain ...
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4answers
5k views

Download single and specific block for study purposes

I just started studying bitcoin. I would like to be able to download a single block from the Bitcoin network. This should be an old block, already mined, and which I can know the nonce. Then I ...
2
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2answers
1k views

Difference between transaction chain vs blockchain

What are the difference between transaction chain in bitcoin and blockchain used in bitcoin? Is it sufficient to say to each transaction refers to previous transactions in the transaction chain and ...
1
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1answer
128 views

Would nine 1MB transactions potentially create havoc on the BitcoinCash network

It appears that the BitcoinCash chain is still on its original BCH main chain, and non-upgraded mines/exchanges/wallets can still transact there. What then would happen if nine (or more) 1MB ...
16
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3answers
8k views

How to calculate new “bits” value?

Every 2016 blocks one needs to calculate new bits value. What is the formula to calculate it?
0
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1answer
71 views

Full node storage requirements for new 2MB block which is only 10% full

If blocks were 2MB, and a 2MB block that is only 10% full gets confirmed, then how much additional storage is required on a full node? I am guessing the correct answer here is 200K? Thanks in ...
0
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2answers
138 views

Bitcoin Core LevelDB Index saves forked blocks

I've noticed that bitcoind will permanently save unverified blocks that it receives even if they turn out to be small blockchain forks, likely occurring from the relatively simultaneous discovery of ...
8
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2answers
4k views

What is chainwork?

If I run the RPC call getBlock on the bitcoin-qt client it gives me field called chainwork containing a hash. I cant find any information what this value is about. Request: getblock ...
1
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2answers
445 views

Valid block on top of invalid block

I have been researching a little on the concept of blockchain for some time now. If there is any corrupted block then others won't try to build blocks on top of it. But suppose for some time if it ...
2
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1answer
118 views

How are transactions in forks verified efficiently?

In this answer here, it's stated that Bitcoin uses a hashtable of all currently unspent outputs, in order to verify that the inputs of transactions haven't already been spent. How does this interact ...
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4answers
61 views

Why blocks are validated instead of transactions?

In most of the conventional blockchains, blocks are validated instead of transactions. Why cant' transactions validated directly? The structure of basic blockchains are linked lists, by having DAGs, ...
0
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1answer
105 views

Would mining future bitcoins break the bitcoin?

assuming an bitcoin miner with very much hashrate like bitmain would decide to mine "future" bitcoin blocks and provide them within very short time to the network, would this break the bitcoin? As i ...
0
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1answer
69 views

How are mined blocks broadcasted in a distributed environment?

I understand that after the golden nonce is found by the miner he broadcasts the block and the other miners verify it. But I don't understand how they broadcast it because bitcoin is completely ...
3
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4answers
375 views

Why miners need to broadcast blocks that contains full transactions in Bitcoin?

Does anyone know why Bitcoin requires miners to broadcast blocks that contains full transactions? When a user want to make a payment on Bitcion, he/she needs to broadcast a signed transaction, and ...
1
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2answers
805 views

BlockChain scalability: How does BlockChain process multiple parallel transactions?

I just did some introductory research into blockchain technology and this is a breakdown of my understanding of how it works: Scenario: Assume Trump wants to send Obama 5 bitcoins. As soon as this ...
16
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3answers
6k views

What is the number of transactions in a block?

What determines the number of transactions that can be validated in a block?
1
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1answer
56 views

When we're calling `getrawtransaction` how does Bitcoin-core calc and verify confirmations?

if a transaction has 10 confirmation, does bitcoin-core check if the txid exists in the last 10 blocks? or its calculated based on transaction block number?

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