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Questions tagged [difficulty]

This tag should be used for questions regarding difficulty which encodes the likelihood of one hash to succeed at mining a block. Indirectly, it is a measure of the total hashing power of all miners for a given cryptocurrency.

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where in the source code is the the proof of work checking the blockheader hash and nonce?

Where in the source code do we check whether hash(blockheader*nonce) < Difficulty In fact, the line I found is as follows: https://github.com/bitcoin/bitcoin/blob/v0.17.0.1/src/pow.cpp#L87 My ...
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22 views

bitcoin's PoW, real time of creating one block

i learn that bitcoin is created every 10 minutes and if block is created faster than 10 minutes, Difficulty will increase. and study deeper, mining process is finding nonce that start 0 to increase 1 ...
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1answer
26 views

mining difficulty is not changed on regtest

I want to see the automated mining difficulty change on regtest but it did not change even I generated 2016 blocks. How can I see it? // initial difficulty $ ./bitcoinA/src/bitcoin-cli -rpcuser=...
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2answers
51 views

Mining: what is the lowest possible target? Could it be a block hash of all zeros?

I had a basic question about Bitcoin mining. I understand that as the bitcoin difficulty adjustment becomes harder the hash output will require more 0s in the beginning of the hash. Is it ...
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2answers
36 views

Difficulty Adjustment Compairson

Thinking about different difficulty adjustments for protecting new coins against attacks from big miners. 2017 when BCH forked from BTC, BCH added the EDA (emergency difficulty adjustment) and updated ...
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1answer
32 views

where is the adjustment calculation for the target value in the source code?

Can someone point me to the source code and explain how the average is calculated for the adjustment of difficulty that takes place every 2016 ? Update: i have consulted with previous questions but ...
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1answer
33 views

Why is Target < Blockhash?

I am currently trying to validate a blocks hash against its target in python3: This is a block in the Blockcypher testnet, and I am using this formula from the Bitcoin Wiki. block_hash = '...
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2answers
58 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 ...
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1answer
34 views

is the proof-of-work for safety or efficiency?

i am reading the proof-of-work (aka: pow, target threshold, difficulty, etc.); my understanding is that pow adds a requirement to validate block headers, so that both benign and malign nodes need a ...
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1answer
35 views

How does difficulty impact profitability? what is the formula?

I have an Antminer S9 ASIC miner , and I have visited this , but I want to know how difficulty may impact my profitability in the future. I would also like to estimate break even costs.
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79 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. ...
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19 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 ...
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1answer
25 views

Why can I observe three different network difficulties in a span of a few days?

https://www.blockchain.com/charts/difficulty If I study the difficulty changes the last 6 months, I can see, as would be expected, that roughly every two weeks, the network makes an appropriate ...
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1answer
18 views

When update mining difficulty, Is the timespan of the past 2016 blocks approximated value?

I know how to calculate difficulty, and I know it is increased or decreased by checking the timespan of the past 2016 blocks. and I found actual code for calculating timespan: https://github.com/...
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1answer
30 views

Have all hashes of unlocked difficulty levels of cryptocurrencies been mined?

I'm wondering if all the hashes of a previously unlocked difficulty level of a cryptocurrency, such as 0000000000000000xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx BTC , have been completely ...
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1answer
37 views

Mining a new block

Hypothetically, if you only have one node mining in the network, how much time does it take to solve for the nonce assuming for example the current difficulty?
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133 views

How to calculate coins mined per day?

Sorry for the noob question I'm pretty new to crypto coins and all this stuff. :) I wonder why the formula <your hashrate> / <coin difficulty> gives the mined coins as a result...Formula ...
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1answer
71 views

How is the target in Bitcoin set? Who does this?

I want to understand how the target value is adjusted or by whom in Bitcoin. I know that the hash of a block + nonce must be lower or equal to the given target for mining. Who sets this target ? If ...
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1answer
19 views

How difficulty variation is technically linked to time take for the block discovery?

Can anybody explain to me technically in units about the time relation to difficulty variation in bitcoin mining e.g. if a block is discovered in 10 minutes, does T = 10 minutes? or T = 20160 minutes ...
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1answer
111 views

Is there a limit to how many blocks can be rolled back from a 51% attack?

I was wondering if we where to ever face a 51% attack is there some sort of limit as to when the longest chain doesn't matter? For example if I owned 51%+ of the network, mined 1000 blocks privately ...
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2answers
262 views

Why aren't block hashes used directly as scores for difficulty purposes?

Why does Bitcoin apply a difficulty function to block hashes and then use the output of this function to add up and determine the "longest" chain? Why not just e.g. add together all block hashes (as ...
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1answer
383 views

Testnet difficulty change

Has something changed recently in testnet? Today I've been seeing new blocks appear every 1-5 seconds instead of the usual 10-20 minutes
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53 views

Why is the target truncated?

Reading the docs on target: The maximum target used by SHA256 mining devices is: 0x00000000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF Because Bitcoin stores the target as a ...
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66 views

Is there any way by which we can see when was last time or which was the block that was created just before bitcoin adjusted its latest difficulty?

I guess if we start doing mathematical calculation then we can easily find exjact block no which was formed just before difficulty was adjusted. But is there anyway around like by using RPC by which ...
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32 views

How are difficulty level and block reward determined and stored in decentralized fashion in Bitcoin? [duplicate]

I know the difficulty level and block reward are periodically adjusted in Bitcoin to keep the block time approximately to 10 minutes. I guess these are not determined by a central authority but ...
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1answer
42 views

Special min difficulty rule for testnet

I heard about this "special difficulty rule" for testnet, which allows blocks with timestamp 20 min later than the last block to have the min difficulty target. So does it mean that the miners can ...
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0answers
22 views

Where can I find data on average difficulty increases per day, week or month?

I'm aware mining difficulty is very difficult to predict. So, most people do estimations based on historical data. Many calculators display an estimated percentage difficulty increase in a period of 1 ...
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157 views

In Math or Python notation - How to convert bits to difficulty?

Questions What are the equations to convert between bits and difficulty? & understanding bits and difficulty in a block header ask how to convert between bits and difficulty. Unfortunately, I ...
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61 views

Calculating the target from the hash leading off bits

I'm implementing my own cryptocurrency and I found it that saving the "hash difficulty” as the leading off (0) bits of a 256 bit number in a SHA-256 hash is the most intuitive. I'm struggling to find ...
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1answer
47 views

When computing the hash, do you need anything after the number of difficulty bits?

I'm going to screw up a lot of the terminology here. I'm trying to understand the Bitcoin algortihm and wanted to use this JS miner -- https://github.com/howardchung/jsminer . Specifically, I'm ...
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1answer
37 views

Why is explorers shows different difficulty values?

Just take a random block for example, for block 506068, blockchain.info shows difficulty as 2,603,077,300,218.59, while blockcypher shows 392,962,374, do the explorers use a different way to calculate ...
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98 views

Why mining pool has different connections ports for different difficulty

In the documentation of mining pool I found following Connect Details: (Difficulty 5 - GPU) stratum+tcp://stratum.btcprivate.org:3032 (Difficulty 10 - GPU Farm) stratum+tcp://stratum....
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2answers
76 views

Does a logical mining pool assign harder and harder difficulty to the same miner?

Although every mining pool can do things differently, I wanted to get a handle on how a logical pool would behave. If a miner joins the pool and solves a hash at a low difficult, submits the result ...
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102 views

Why do pools give rewards to miners who solve problems at a lower difficulty than the network?

I'm trying to understand why a pool would want to give rewards to miners who mine at low difficulty. Please tell me where this logic falls apart. If the network difficulty is a nonce ending in 100 ...
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579 views

Probability of Finding a Block

I've been using cryptocurrency revenue calculators and have appeared to figure out that for all of the major algorithms, the probability of a hash being valid is 1/(D*2^u) where u is either 0, 13 (...
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1answer
794 views

understanding bits and difficulty in a block header

This block: https://blockchain.info/block/00000000000000000025c089d0a7b2bf6241888c4dd90ab7a4c4baa6a2823551 Shows difficulty at 3,007,383,866,429.73, and bits at 392009692. If I want to see how many ...
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2answers
788 views

How do nonce and difficulty relate?

Good morning, I'm reading about Blockchain technology but I have a couple of questions about the nonce that I cannot find the answers for. I'm hoping someone here will be able to answer them. i) ...
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1answer
466 views

Share difficulty and hashrate

Can anybody explain relations and formulas between mining share difficulty, target and hashrate? Thank you.
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580 views

Why does bitcoin mining take so long?

I was wondering that a block (Here's a Block #506398) It's nonce is 1,229,291,212 (A little over a billion), Then why does it take so long to mine a block because my system alone can do about 500 GH/...
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1answer
52 views

Why can't a Bitcoin fork take over?

According to this question's answers, the difficulty is entirely a result of previous info on a blockchain: How is difficulty calculated? So why can't someone simply fork an earlier state of Bitcoin'...
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1answer
292 views

How is nbits calculated?

When generating a new block, how is the nbits field in block header calculated? Is nbits calculated for every new block like: nbits=nbits of last block * (timstamp of lastblock-timestamp of (...
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200 views

what is preventing me from changing difficulty every submit when pool mining?

If I do pool mining at difficulty=1000 and I find a share with difficulty=2000, I can tell the pool that I was mining at difficulty=2000 and then submit the share. I can earn more in this way. Does ...
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1answer
146 views

Is the difficulty in mining a function of how much total mining power there are in the ecosystem?

I'm trying to understand how difficulty works in bitcoin mining. I understand that as there are less and less bitcoins left to be mined, the amount you get for each new block is lowered. The bit I ...
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1answer
76 views

Will there be a problem if bdiff and pdiff are slightly different?

Considering bitcoin target is 0x00000000FFFF0000000000000000000000000000000000000000000000000000 and pool target is 0x00000000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF. Won't pool miner ...
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2answers
272 views

How to lower difficulty on blockchain?

I created a coin (hexco.in) The problem now is, sometimes some user create pools and use rented mining rigs to mine on my coin. But after a while they stop and my blockchain stucks at a certain block....
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1answer
249 views

Why max target is not (2^256 - 1)?

I'm reading https://en.bitcoin.it/wiki/Difficulty And I don't get why max target is not (2^256 - 1) which is 0xFFFFFFFFFFFF... but 0x00000000FFFF...?
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2answers
213 views

Why does Bitcoin adjust the difficulty every 2016 instead of 2048 blocks?

I am reading Bitcoin wiki and it says over the previous 2016 blocks. Can be further simplified to D * 2**32 / 600 without much loss of accuracy. I guess the reason of reducing to 2**32 is ...
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8answers
15k views

Can bitcoin exist without miners?

In the past year only, the bitcoin mining difficulty has increased fivefold. If in the coming years the difficulty increases so much that mining is no longer profitable (i.e. consumes more power than ...
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1answer
87 views

Can a two-block-sized chain override the main chain?

After i read this: Honest generators only build onto a block (by referencing it in blocks they create) if it is the latest block in the longest valid chain. "Length" is calculated as total combined ...
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86 views

What would be the consequences to lower the difficulty such that a block is generated every 5 minutes?

The difficulty is adjusted such that a block is generated every 10 minutes. What would be the consequences to lower the difficulty such that a block is generated every 5 minutes?