Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [block]

This tag should be used for questions related to Bitcoin blocks

0
votes
0answers
12 views

Byzantine fault tolerance and blockchain: Can this work? Feedback [on hold]

I’m a software developer and I was wondering if this can work (According to my point of view it could work but I’d like to get some feedback) Two types of Nodes: Proposers, Validators. 1) Proposers ...
1
vote
1answer
31 views

How can block time and block size be fixed when transaction volume is constantly increasing?

As I understand it the network rejects blocks over 1MB, and block hash difficulty is set after each block is created as to keep the block time close to 10min. But if people are constantly joining ...
0
votes
1answer
30 views

what happens if a miner include a transaction already exists in another block?

Suppose that I have a Transaction A. (txA) I send my txA to bitcoin network and full node validate it and put in Mempool and starts to broadcasting it. A Miner A connect to a fullnode to create a ...
0
votes
1answer
20 views

Private Blockchains: Validation

I'm a software developer, and I have some questions about private blockchains, I'd like to have technical answers since I'm trying to understand blockchain at a code level. I'm going to write a ...
-1
votes
0answers
10 views

Does a new initialised blockchain contain any predefined values except the nonce?

If i want to create a blockchain, i create a (so called genesis) block and create a hash from it. For example i assign 0 as nonce for the first block Do i have to pregenerate all blocks (maybe empty ...
0
votes
1answer
29 views

How does a node decide whether a block is valid?

I'm a software developer, and I've been trying to figure out how a node decides whether a block is valid, I do understand the hashes in bitcoin, the merkle root, and all those aspects but my question ...
-1
votes
1answer
16 views

How to prevent nodes from creating only small blocks to earn fee?

I read What are the minimum sizes for transactions and blocks in Bitcoin? that there is no min limit - just a max limit of 128MB - for a block. For example if a miner always takes a single ...
0
votes
2answers
41 views

What Opcodes are used to store a file within Bitcoin?

At a block-to-block level, what is actually encoded at a byte[] level to encode a file stream?
0
votes
2answers
25 views

What is the most optimal way to parse a raw bitcoin block with python?

Let's say one is connected to a zmq socket and listening for rawblock. How you'd parse the block header is as follows: block_header = raw[:80] version = block_header[:4] prev_merkle_root = ...
-2
votes
0answers
23 views

How to create the block hash for a dash block?

Apparently dash doesn't use the same hashing algorithm bitcoin uses, but instead uses something called x11 hashing. Does anyone know the formal steps from raw block to block hash?
0
votes
1answer
28 views

Getting individual block by height from Bitcoin P2P network

Is it possible to request an individual block from the bitcoin network, using the block height as parameter? Or would one have to start a node and wait until all blocks up to the desired height have ...
1
vote
2answers
34 views

What exactly makes altering of data in non-bitcoin blocks hard?

If leading zeros is only bitcoin requirement, then what makes altering of data in blocks hard? Like now its easy to modify a block and generate new hash for every subsequent blocks since generating ...
2
votes
2answers
49 views

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.
2
votes
2answers
38 views

Each full node has different mempool?

I don't understand if each full node has different mempool inside. With RPC command getblocktemplate I can Get the information about candidate block. I can Find all transaction verified but ...
2
votes
1answer
27 views

Explanation of a block's fields one by one?

We can get bitcoin block data as JSON by command bitcoin-cli getblock <hash> 2, following is one for height 100000: { "hash": "...
6
votes
1answer
1k views

Why is increasing block size in the Bitcoin network considered to decrease security?

I have been doing some research on the Bitcoin Cash hard fork and the main contention of increasing the block size appears to be the possibility of less security on the network. How does an increased ...
4
votes
2answers
57 views

Why are block header bits necessary? (Valid difficulty is already implied by chain history)

Difficulty or target is implied by chain history, so why does it need to be explicit in the header? I suppose it exposes miner-intended-difficulty, but I don't see why that would be relevant without ...
2
votes
1answer
86 views

Why is a “first seen” rule is used to pick a side in a honest split, instead of deterministic criteria? [duplicate]

I was just thinking, why nodes pick the first block they see when there is an honest split, instead of picking, for example, the one with the "best hash" (number further away from the difficulty cut)? ...
1
vote
3answers
71 views

Block Validation: who does it? How much it costs? And is it present in all protocols?

Different threads were posted in order to clear up this question, but there are some points that I would need to confirm: When you become a full-node (NOT miner, you just downloaded the full ...
1
vote
2answers
49 views

mining: losers get nothing?

if the winning miner takes the 12BTC+fees, unless you own the biggest mining operation out there, or are not a member of the biggest pool, why bother mining, if there is no prize for second place? ...
1
vote
1answer
42 views

identical coinbase transactions

this sounds like an old topic but i have not found a satisfying answer yet; in history there lived two blocks with identical coinbase transactions: https://www.blockchain.com/btc/block-index/106662 ...
1
vote
1answer
27 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 &...
1
vote
0answers
76 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. ...
1
vote
1answer
52 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 ...
1
vote
0answers
18 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
votes
1answer
19 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', ...
1
vote
1answer
43 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 ...
0
votes
2answers
35 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
votes
2answers
61 views

Is there any python library could be used to decodescript in output

For example decode the ScriptPubKey like 4104678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5fac to some data like ...
0
votes
1answer
14 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
votes
1answer
20 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
votes
1answer
22 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 ...
5
votes
2answers
565 views

Shortest and Longest block interval time ever recorded in Bitcoin

Bitcoin block interval time is on average 10 minutes, that is the difficulty is adjusted in such a way that every 10 minutes a miner will manage to find the right hash. This is just an average time ...
2
votes
1answer
49 views

Different balances in API block explorers for BTC

BTC.com block explorer shows bigger balance than for example Insight or Blockchair. For example: https://btc.com/1FLDCfr9iG7n6bAdGsqBXmhaLgC4aSze72 https://insight.bitpay.com/address/...
0
votes
1answer
35 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
vote
1answer
47 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 ...
1
vote
1answer
15 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
vote
1answer
52 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
votes
2answers
48 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 ...
2
votes
2answers
52 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
votes
0answers
34 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
votes
2answers
36 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
votes
2answers
92 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
votes
1answer
102 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
votes
1answer
39 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 ...
0
votes
1answer
106 views

How do I double SHA-256 the header of block #59,500?

I'm not sure how to combine all of this information. https://blockchain.info/block/00000000096af43105123c499521e1d131d172e7e1bf2ed0843290a921f1f6a7 Version 1 Time Bits 470771548 (is this the right ...
1
vote
1answer
146 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?
0
votes
0answers
26 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. ...
1
vote
1answer
66 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 ...
1
vote
1answer
102 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 ...