Linked Questions

9 votes
2 answers
2k views

Where exactly is the "off-by-one" difficulty bug?

I read through How is difficulty calculated? and want to understand where the "off-by-one" bug is in calculating difficulty. Here is a Matlab snipet I wrote to calculate difficulty. What are the ...
5 votes
2 answers
188 views

Will Bitcoin scaling affect the amount of hashing power required to keep the network secure?

In Mastering Bitcoin Andreas Antonopulous asserts that "Bitcoin can scale up, achieve broader adoption, and remain secure without any increase in hashing power from today’s level." Is this really ...
71 votes
2 answers
95k views

Can someone explain how the Bitcoin Blockchain works?

I'm trying to figure out how the blockchain works and how to read it via blockchain.info website. Is there a laymen way of explaining how the block chain works and how to read the blockchain to trace ...
9 votes
3 answers
9k views

How is the target section of a block header calculated?

I've been poking around https://en.bitcoin.it/wiki/Target and I've found the current target, but I can't seem to find how it's generated. It's supposedly generated when the difficulty is adjusted, as ...
12 votes
2 answers
8k 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 can't find any information what this value is about. Request: getblock ...
0 votes
2 answers
221 views

Why does SHA256 miner hash have to be lower than the current target 256bit hex? [duplicate]

I'd like to ask if someone can help explain this definition found on https://en.bitcoin.it/wiki/Target "The SHA-256 hash of a block's header must be lower than or equal to the current target for ...
28 votes
3 answers
17k views

What is "difficulty" and how it relates to "target"?

I don't understand what "difficulty" means and how it really relates to "target". I understand what "target" is - it tells the miners, how small the resulting hash should be. (Basically, how many ...
0 votes
0 answers
12 views

consensus on the moving average [duplicate]

I research on consensus and need a forced delay between submittability of new blocks. In bitcoin you use stochastics + processor clock speed. This allows you to choose an expected forced delay, which ...
0 votes
1 answer
116 views

Want to verify previous block hash and prove of work

I want to verify several random blocks and check if there was prove of work really found. I need it for some reasearch reasons. I have downloaded the blocks historical info and there are only hashes ...
0 votes
1 answer
316 views

ELI5: does the number of 0's required in mining for SHA256 over the years strictly increase, or does it depend on how many miners there are?

It is said that to discover a block, the person has to get a SHA256 number that has all 0's for the first 72 bits. Does this number 72 change and become bigger and bigger over the years (say, every 4 ...
-1 votes
1 answer
104 views

I've built a bitcoin miner and mined. Now what I do?

I've mined bitcoin to test and understand cryptocurrency better. Which generated this hash 00000431fb66ed96815b3829e975c2235a64b9a646c0bd1cc526dc1727c1f16b(nonce value of 300712) What I do with this ...
0 votes
1 answer
46 views

What is the difference between hash-target and the previous hash? [duplicate]

Is the target that the requirements have to meet a number that is set by the network that is always the same, or is the target the hash from the previous block?
1 vote
1 answer
91 views

How a real mining code treats difficulty?

I have come up recently with "how to mine bitcoin using python" or "how to mine bitcoin using golang" and as I have been observing all these source code, not only I'm confused but ...
5 votes
1 answer
417 views

Why is two hours the maximum acceptable offset for Bitcoin blocks?

As far as I understand, Bitcoin transactions include a timestamp, but the only requirement is that they don't differ for more than two hours. But why two hours? For computers that are constantly ...
5 votes
2 answers
3k views

Isn't Bitcoin's hash target supposed to be a power of 2?

From Bitcoin's whitepaper I've gathered that the hash of a block must start with a certain number of zeroes. And that this number of zeroes is adjusted every 2 weeks. Consequently the hash target is a ...

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