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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.

44
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8answers
16k 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 ...
5
votes
1answer
315 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 (...
2
votes
4answers
3k views

Where to get difficulty data for all crypto coins?

I need to get difficulty data and exchange rate for past 10 days for making a graph out of it (i.e., for all coins). Can anyone suggest where can I get it?
1
vote
1answer
22 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/...
1
vote
1answer
24 views

Which is the better estimator for future mining intervals, the 10 minute protocol target or the observed, historical average?

The Bitcoin protocol is designed so that the network difficulty is periodically adjusted so that new blocks are mined on average every 10th minute. However, looking back the last 10 years, it appears ...
1
vote
1answer
42 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.
1
vote
1answer
81 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 ...
1
vote
1answer
42 views

Is the bits field a unique representation of the target?

The bits field is the compact representation of the target. Example: bits: 1d00ffff target: 00ffff0000000000000000000000000000000000000000000000000000 bits: 1cfff00 target: ...
0
votes
2answers
80 views

Mining Difficulty and Leading Zeros

I understand that the Bitcoin mining problem is to find a string s (hash of previous block + Merkle Tree Hash + nonce) such that sha256(s) has n leading zeros, where n determines the mining difficulty....
1
vote
0answers
37 views

How difficult is it to confirm a Bitcoin Block?

If I have done the math right to come up with this hash, to confirm a true block and this is a confirmed hash. You can look it up here Bitcoin Block #570240 ...
0
votes
1answer
45 views

bitcoin difficulty determination

Given the bitcoin difficulty information in https://bitcoinwisdom.com/bitcoin/difficulty, determine the bitcoin difficulty on April 1, 2019 and April 1, 2020. State any assumptions made in this ...
5
votes
1answer
821 views

Creating Mining Competition on regtest

As we know , Bitcoin core-Regtest is used to set up our own blockchain starting from Genesis Block. I have created Two nodes on my localhost running on different ports (I am using Windows 8.1). They ...
0
votes
1answer
59 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=...
0
votes
0answers
39 views

How to calculate difficulty re target?

I am trying to re-calculate difficulty and verify by using the formula T${new}$ = T${old} \times \frac{Time~ taken~ for~ previous~ 2016~ blocks}{2016~\times ~600}$ I used block #s 564697 and 562681 ...
1
vote
1answer
48 views

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 ...
0
votes
1answer
32 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 ...
1
vote
1answer
77 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 ...
1
vote
2answers
74 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 ...
57
votes
3answers
30k views

How is difficulty calculated?

Can anyone explain me in the plain English how difficulty is calculated. I have a very approximate understanding that it is calculated based on the amount of hash power in all the bitcoin community ...
0
votes
2answers
42 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 ...
4
votes
2answers
268 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 ...
2
votes
1answer
38 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 ...
1
vote
1answer
41 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 = '...
4
votes
2answers
71 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 ...
0
votes
1answer
36 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 ...
17
votes
1answer
13k views

Relationship between Hash-Rate and Difficulty

What is the algebraic relationship between Total Network Hash-Rate and Difficulty?
5
votes
3answers
6k views

Why is mining difficulty increasing?

I have heard in many places that mining difficulty is increasing, meaning that the hardware used to mine new coins will need to be more and more powerful as time goes on. What is pushing mining ...
1
vote
0answers
100 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. ...
3
votes
2answers
354 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
vote
0answers
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 ...
5
votes
3answers
280 views

Bitcoin value vs. Supercomputing

What protects the stability of Bitcoin's value if supercomputers or some other technological breakthrough allows them to be mined at rates we have not anticipated?
0
votes
1answer
27 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 ...
2
votes
1answer
1k views

What would happen if 90% of the Bitcoin miners suddenly stopped mining?

What would happen if 90% of the Bitcoin miners were to suddenly stop mining Bitcoin, i.e. the Bitcoin network's hashing power would drop to 10% of the previous amount. Would it become more difficult ...
0
votes
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 ...
1
vote
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?
0
votes
1answer
664 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 (...
0
votes
1answer
229 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 ...
4
votes
1answer
443 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
1
vote
1answer
86 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 ...
0
votes
1answer
20 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 ...
2
votes
1answer
142 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 ...
3
votes
1answer
1k views

What does the nBits value represent?

When a miner hashes a blocksheader and it produces a hash that is lower than the value represented by nBits then the PoW is considered solved. What exactly does this mean? For example a SHA256 hash ...
22
votes
2answers
11k 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
1answer
62 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 ...
0
votes
3answers
267 views

What effect will the halt of the use of cpu-gpu miners have in the difficulty?

Do u have an estimate about what will happen when more powerful machines make the simple gpu use unaffordable? This would practically mean that significant part of the mining will halt. You think ...
1
vote
1answer
68 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 ...
0
votes
1answer
34 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 ...
52
votes
4answers
29k views

What keeps the average block time at 10 minutes?

I've been told "the network" sets the difficulty level such that there will be one new block mined every ten minutes. I imagine the rich would instead prefer to keep difficulty as high as possible to ...
16
votes
3answers
7k views

How to calculate new “bits” value?

Every 2016 blocks one needs to calculate new bits value. What is the formula to calculate it?
1
vote
1answer
187 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 ...