# 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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### What is the endianness of the target?

Let's take the latest bits value, at the time of writing: 0x170355f0 And convert it to the target: 0x0000000000000000000355f00000000000000000000000000000000000000000 When comparing a candidate block ...
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### Relation between difficulty and number of leading zero bits in hash? [duplicate]

What's the relation between the difficulty and the number of zero bits in the hash? For example, as of writing, the best hash is: 000000000000000000028a424dde3445bfe99f5097b513b245c5a5a9bded20c4 This ...
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### What is the lowest possible value for target?

Similar question was asked here but the answer doesn't really provide an answer. This answer says that the lowest possible value for target is "all zeros plus a one". Pieter Wuille in the ...
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### Why does the Stratum protocol use a Share Difficulty of 2^32?

In the comments below his answer to my recent question about Network Difficulty, Pieter noted that Stratum Share Difficulty is an entirely separate concept. See https://bitcoin.stackexchange.com/a/...
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### Is the maximum target a consensus rule?

What is "difficulty" and how it relates to "target"? states that the largest possible target value (max target value) is: ...
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### What is the numeric precision of Network Difficulty?

My understanding is that Difficulty (aka Network Difficulty) is an approximate representation of the Target, a 256-bit number which is hard to reason about or work with in human-readable Decimal ...
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### Calculating daily mined BTC

Hopefully an easy Question. I was updating some data tables and wanted to estimate monthly yield based on difficulty and known hashrate of the miner in this cash 110 TH/S. I had it in my head the ...
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### Would it work just fine if "bits" was set to "1cd86a52" instead of "1d00d86a" at the first difficulty adjustment?

The first difficulty adjustment on the network happened at block 32256. The time for block 32255 (one block before the adjustment) is 1262152739 and the time for block 30239 (2016 blocks before the ...
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### Breakdown of BTC mining and correlation with past metrics

I am having trouble understand the current BTC market. Do current (technical) indicators like mining difficulty, hashing power, electricity costs not mean that the price should be trending upwards?
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### Is it possible to create an output locked to a specific mining difficulty target?

When the network sees a block appear with enough difficulty nodes can detect this as potentially the longest valid chain allowing the blocks miner to officially claim the block reward via coinbase ...
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### What is the nBits field in the CBlockHeader class?

In the source code for the CBlockHeader class, there is a field called nBits. /** Nodes collect new transactions into a block, hash them into a hash tree, * and scan through nonce values to make the ...
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### Delay time for the second block of Bitcoin blockchain

According to the data stored in the blockchain, the genesis block is mined at Jan 03, 2009. The second block is mined at Jan 09, 2009, 6:24:25 AM. Which is 6 days later. At first, it seems rational to ...
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### Could you hack Bitcoin / Proof of Work with one leading zero for each block?

I believe that in Bitcoin, if you would like to replace the chain, you need to pass 3 conditions. You need to have a longer chain (more blocks), you need to have a greater total difficulty (the ...
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### How to calculate nBits from target?

I was wondering how the nBits are calculated from the target, I know how the the target is calculated from nBits, but how is the nBits calculated from the target?
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### Proof of work: comparing computed hash with target hash

According to the source code here is where the hash computed by a miner is compared with the target hash: bool CheckProofOfWork(uint256 hash, unsigned int nBits, const Consensus::Params& params) { ...
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### How to estimate pool hashrates based on the number of blocks they have found?

What is the formula used to estimate the pool hashrate based on the number of blocks found by that pool? For example, Braiins provides an estimated hashrate that is calculated based on the amount of ...
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### cw-144 oscillation problems [closed]

I am starting to get into Difficulty Algorithms and attacks on them. I came across cw-144 which used to be BCH's DAA at least until mid 2020 (recent developments do not interest me and this is not the ...
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### Does difficulty target remains static for 2016 blocks in Bitcoin?

I know that in Bitcoin the difficulty target adjust after creating 2016 blocks. So, it means that within these 2016 block the difficulty target remains same (static). Am I correct? If this is correct ...
1 vote
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### Bitcoin hash rates/difficulty

i read that some ASIC cards can produce upto 100 TH/s (= 100,000 bn hashes/s = 100 tn hashes/s) Further, lets say network difficulty at the moment is 30tn (i understand this to mean that on average it ...
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### What's the logic behind the way block proofs (in GetBlockProof) is calculated?

Bitcoin Core uses GetBlockProof() function to determine the contribution of a block to the total difficulty of the current chain, aka, nChainWork in CBlockIndex. I'm having trouble understanding the ...
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### 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 ...
1 vote
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### How often does target hash change and how to find it?

So basically I was researching target hash and trying to figure out how I can find it. I know there are posts out there that have said that Bitcoins target hash is a 256 bit number with 32 bits of ...
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### How does the bitcoin network difficulty syntax work?

So, essentially what my question is what does the "syntax" of a bdiff (bitcoin target difficulty) look like? I know that its a number, i.e the current network difficulty is set at around ...
1 vote
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### Does the length of the blockchain affect computing power needed to verify transactions?

As the blockchain for something like BTC grows, does that affect the time needed to verify new transactions and/or the integrity of the blockchain? From my understanding, miners only verify the hash ...
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### How do you derive "0x008000 is the smallest legal value for the lower 24 bits since targets are always stored with the lowest possible exponent"?

From https://en.bitcoin.it/wiki/Difficulty: How is difficulty stored in blocks? Each block stores a packed representation (called "Bits") for its actual hexadecimal target. The target can ...
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### What's the point for mining pools to set a higher target?

I'm reading the Mastering Bitcoin 10th chapter, and quote Similarly, a mining pool will set a (higher and easier) pool target that will ensure that an individual pool miner can find block header ...
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### can the network stagnate if the difficulty grows too big?

So im mainly thinking in the very early days of bitcoin when the networks compute power was minimal. What would happen if say a big organization with exponentially more compute power than the network, ...
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### if the lower bound of a blocks timestamps is the median of the previous blocks, how can the network difficulty ever decrease?

according to bitcoin developer documentation the lower bound for a blocks timestamp is the median of the previous 11 blocks. and also according to the documentation the network difficulty is ...
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### Algorithm behind Bitcoin Core's hashes/s metric

The call bitcoin-cli getmininginfo returns a metric networkhashps among others. It shows how many hashes the entire Bitcoin network generates per second. This metric however, is not directly stored ...
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### How do difficulty, hashrate, and network hashrate fit together?

I understand that there are multiple terms for the idea of how hard it is to successfully mine BTC. The terms I have seen are "difficulty", "network hashrate" and "hashrate&...
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### Bitcoin difficulty - why leading 0s?

I do a sort of bitcoin 101 presentation for folks where I work. In one of the recent sessions, someone asked why the proof of work difficulty requires a minimum number of leading 0s. Why not 1s or ...
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### Would Bitcoin still work without a target difficulty?

Suppose that Bitcoin nodes had no target difficulty at all, and instead just accepted the block with the largest PoW every 10 minutes. Ignoring the increased bandwidth (since nodes would be ...
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### 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 ...
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### Choosing main chain based on difficulty

If a node observes a fork in the bitcoin chain, then the node will choose the chain that has the highest difficulty (sum of difficulty in each block of the chain). But the difficulty changes only once ...
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### Why does the Genesis block appear to have a lower hash than necessary?

The hash of the genesis block of bitcoin has two extra 0 as compared to other block hashes. According to the logic, it should have been the same as they all have the same difficulty. Why is it so? Was ...
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### Making the block reward dependent on the difficulty?

I am looking for papers which discuss, if making the block rewards dependent on the difficulty could be used to curb excessive PoW growth. Idea is that BTC price roughly drives difficulty and energy ...
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### What does it mean to make mining more difficult? [duplicate]

Really I don't know nothing about bitcoin but now I got curious read something and immediately come to something on mind. I mean, there's a social economic comunity somewhere generating value based on ...
1 vote
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### Cant understand how share difficulty affects my chances in solo mining with a pool

So obviously I am not solo mining bitcoin but I think the underlying principles are the same so you guys could help me out here. I am solo mining ergo on a solo pool (herominers solo pool) What I do ...
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### What is the meaning of difficulty in Bitcoin mining?

I'm a beginner in Bitcoin and Blockchain technology, so I have a question after reading about the difficulty in Bitcoin mining: What does the difficulty actually mean? I read that A high difficulty ...
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### Bitcoin difficulty: One block with very high difficulty vs. long chain with accumulated difficulty

First assume the hypothetical scenario, that someone has infinite hashing power, starts with the genesis block and mines one block, that has higher difficulty than the whole "normal" ...
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### 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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### How is the Max Target of a Genesis Block Decided?

I've been diving into the world of Blockchain and crypto lately, trying to build my understanding of mining specifically. I understand that in POW systems, the difficulty of the first block is 1, and ...
1 vote
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### How is "cumulative PoW" calculated to decide between competing chains?

Chain 1 has blocks with targets diff1, diff2, diff3, diff4 Chain 2 has blocks with targets DIFF1 DIFF2 DIFF3 What's the formula to derive the (relative) cumulative proof of works from these chains to ...
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### Was Bitcoin originally designed to be easy to mine?

I’ve read that back around early 2009, Bitcoin was so easy to mine that an old laptop could mine hundreds of coins in a day by simply using a CPU. Was this Satoshi’s original idea for how people ...
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### What would happen if mining difficulty would be decreased to almost nothing?

What would happen if Bitcoin mining difficulty would be reduced to nothing/very easy? I can only think of the benefits such as exceptionally lower enery waste and much faster transaction processing. ...
1 vote
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### Is there an easy way to estimate the number of mining nodes?

I was curious about the number of mining nodes on the network, yet I haven't seen it discussed. I tried two different approaches to approximate the count of mining nodes. I looked up the hashrate of ...
1 vote
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### What would the expected block mining time be if 30% of the total network hashrate disappeared suddenly?

Ignoring the economic reasons as to why this may or may not happen. If for some reason the network hashrate suddenly dropped by 30% immediately after a difficulty adjustment and remained at that ...
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### How are the nBits of a block calculated?

So I've been trying to figure out how the nBits of a block is calculated, but I can't seem to come up with an answer. I know (think) that it's based off the difficulty of the block, but I'm still not ...
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