Questions tagged [block-hash]

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How to get the block hash in the chainstate leveldb?

From this link What are the keys used in the blockchain levelDB (ie what are the key:value pairs)?, to get the block hash I use the obfuscation key and xor it with the result I get from the db. So I ...
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Create a Double sha256 block and trandaction

I have same problem whit create a double sha256 of the transactions and blocks with C++. The hash block it is created with the concatenation of these data, version + previusBlock + merkleRoot + ...
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Trying to understand why hash value is more secure from hash algorithm

I am currently studying in college in the US and was actually curious about bitcoin and cryptocurrencies as a whole. I started looking on free university sites like Stanford university and New York ...
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Proof-of-Stake: How to ensure immutability of the blockchain?

In Proof-of-Work, a miner tries to solve PoW puzzle based on the hash of previous block, such that in case of changing block B_i, all blocks after that (blocks B_i+1, B_i+2, ...) are no longer valid ...
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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 ...
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Why is the nonce bruteforced from 0 to n while mining?

bitcoin noob here. I was wondering why is the nonce increased from 0 to n while searching for a blockhash? Why not start at some other integer > 0 for example? My background is in ethereum-dev, so ...
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218 views

Mining Theory: What would happen if a block hash collision occured? [duplicate]

To my knowledge, neither SHA256 or scrypt have ever had provable instances of hash collisions occur.. However, if this highly unlikely event was to happen, what would that mean for the state of the ...
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478 views

How to decode the block hash?

I got the block hash from zmq. 00000000000000000045c639280aee532c5b12b03c80bfdec7aae674fd8246e0 I want to decode the above block hash. Could anyone tell me how to decode the above block hash?
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How to solve error: Incorrect or no genesis block found. Wrong datadir for network?

I am making my own alt-coin, and I have mined the first genesis block hash(after some time), Merkle hash, nnonce and time. I am running on Ubuntu14.04. But when I run ./bitcoind I get this error ...
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In the case the difficulty increases as much in future, will the possible hashes run out/be insecure?

As I understood, in the block hash, the amount of zero's is the nonce, like this: 0000000000000000005f54622d97866453137466737289c2500e67f6fce1cd4e When there are more blocks found than in the ...
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Why Bitcoin Mining requires “Hash Guessing” problems, even though Consensus algorithm exists to tackle BFTP?

This post on CoinText explains Purpose of Hashing in Bitcoin Mining: The purpose of all the extra work is to prevent the traitors from sending false messages but serves no other purpose. The idea ...
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How To Calculate Merkle Root?

I found this example: Current merkle hash list: 32650049a0418e4380db0af81788635d8b65424d397170b8499cdc28c4d27006 30861db96905c8dc8b99398ca1cd5bd5b84ac3264a4e1b3e65afa1bcee7540c4 Current merkle ...
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647 views

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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1answer
443 views

merkle root 2 codes

While trying to calculate the merkle root in python from the data i got from the mining pool.... i found there are 2 different codes. code 1: def build_merkle_root(coinbase_hash_bin, merkle_branch):...
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Hash that defines previous block in Blockchain vs mathematical solution

Is the hash that defines the previous block (block A) in a new block (block B), the same as the hash the miner calculated to submit block A? As far as I know, you need to find a nonce so that the ...
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1answer
489 views

Leading zeros and numbers of hashes before arriving to solution

Had been reading a post written by Adam Back a couple years back (no pun intended) with regards to calculating bitcoin difficulty in bits (so we could arrive to the number of hashes roughly needed ...
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366 views

Chain with most proof of work - hash target or block header hash?

What is calculated towards the sum of PoW of the chain? Is it the target difficulty that has been met or is it the actual block header hash? Say the target is 000000ABC00000000... and I mine block ...