Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [proof-of-work]

This tag should be used for questions regarding how Proof of Work works and Proof of Work algorithms. Proof of Work is a scheme where a 3rd party can verify that someone performed at least a certain amount of work to produce something. This is used in Bitcoin mining.

0
votes
1answer
199 views

How to start Proof-of-stake phase after pre-mining the coin in Proof-of-work phase?

I am learning to develop a new cryptocurrency on my own, for the same i decided to develop a Proof-Of-Stake coin, I forked the Okcash for this purpose. And was able to change the coin according to my ...
0
votes
1answer
163 views

Is the purpose of proof-of-work the immutability of the blockchain?

I have a disagreement with a person: I believe that the primary and most important goal of including proof-of-work (and therefore the nonce) in a block is to make it hard for an attacker to change ...
0
votes
1answer
13 views

When miner insert coinbase?

when miner create the candidate block with transactions of mempool, insert the coinbase after 'win' PoW or during PoW?
1
vote
1answer
33 views

How to model randomness in validators selection in PoS?

I searched a lot here and on the Internet to figure how how randomness selection of validators in PoS works? I understand it is a random selection based on fraction of stake a validator has, similar ...
2
votes
2answers
444 views

Proof of work - lottery approach

I'm sure I am missing something here. But not sure what ... Proof of work - after all is said and done, when a hash is found (about 10 min), it is said to be like someone hitting the lottery. Anyone ...
7
votes
2answers
512 views

How does a mix between Proof of Work/Stake work? (Peercoin)

I think I understand Proof of Stake and Proof of Work from a conceptual point now. For themselves both are good ideas for sure, but how would a crypto currency like Peercoin (PPC) combine both of them?...
1
vote
2answers
44 views

What is entropy mean in this context?

"The Bitcoin nonce forms part of the block header, which is used by miners to provide entropy as part of the Proof of Work process, to try and find a hash meeting the difficulty requirement." Quote ...
2
votes
1answer
116 views

Byzantine Fault Tolerance Threshold of Bitcoin: 1/2 or 1/3? (Edited)

According to this answer: https://bitcoin.stackexchange.com/a/58908/41513 a Byzantine Fault Tolerant (BFT) consensus threshold is 1/3. On the other hand, there is a common belief that Bitcoin network ...
0
votes
1answer
23 views

What is meant with 'the highest PoW'?

What is meant when the nodes select the chain with the highest cumulated PoW? How is the highest highest PoW calculated? I thought the concept itself is called PoW.
0
votes
1answer
58 views

Permissioned or Permissionless blockchain? Which one is PoS more adapted for?

Since in proof-of-stake (PoS) there is no mining process, according to functionality of permissioned and permissionless blockchains, which type is PoS more adapted for? In the other words, is a PoS-...
1
vote
1answer
45 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
41 views

If all Proof of … systems use mining

I understand how Proof of Work (PoW) works now, and am beginning to look at different Proof of ... systems like these: Proof of Stake Proof of Ownership Proof of Existence Proof of Space From what I ...
1
vote
0answers
39 views

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 ...
9
votes
3answers
2k views

How does proof of work inspire trust when the work is just guessing?

I'm struggling to understand the value added by machines guessing at inputs to create a hash below a target value in order to produce a proof of work. I understand the proof of work is somehow ...
0
votes
2answers
16 views

Is it possible to accurately map hashing power to network size?

Let's say we have a network with n nodes in it. Is it possible, when the hashing power of the network is calculated after a proof-of-work, to accurately estimate n with an algorithm taking the ...
10
votes
3answers
20k views

What's the difference between PoW and PoS?

I'm looking for an explanation of the difference between Proof of Work algorithm and the Proof of Stake and how they relate to Bitcoin and the Blockchain. Also looking for a fairly simple, non-...
0
votes
2answers
160 views

Difference between Hashcash proof of work algorithm and Ethash proof of work algorithm?

Understand that each proof of work algorithm has its pros and cons. Difference between Hashcash proof of work algorithm and Ethash proof of work algorithm? Nathan Aw
0
votes
2answers
78 views

group proof of work

Right now, every node in a Proof of Work system, solves the POW puzzle independently. Is there any concept of group proof of work, where everyone in the group needs to solve part of the puzzle.
1
vote
1answer
180 views

Who decides what the next, correct Nonce is?

As I understand finding the correct Nonce is the basis when hashing transactions for Proof of Work. How and where is this decided in the ecosystem what the next Nonce is? In my limited understanding ...
2
votes
1answer
121 views

What hash algorithm is used in Bitcoin Cash?

I know that bitcoin uses hashcash as PoW algorithm, Ethereum uses EtHash and Litecoin uses Scrypt. But I didn't found anywhere the PoW algorithm used in BitCoin Cash, does it uses hashcash too?
25
votes
4answers
71k views

The bitcoin mining algorithm from a programmer's viewpoint

This page: Blocks said mining is actually to solve a mathematical problem, but reading Block hashing algorithm doesn't give much help. I also tried reading bitcoind source code, but reading code takes ...
1
vote
1answer
570 views

Where can i find proof of work in bitcoin core source code?

does anyone knows which part of the bitcoin core source code contains the proof of work for mining, creating of block and adding to blockchain? what are the files and functions involves? https://...
1
vote
4answers
109 views

Use of proof of work in bitcoin

I am trying to understand what problem in bitcoin proof of work solves and came to this somewhat helpful quote: So, for instance, if a miner controls one percent of the computing power being used ...
2
votes
1answer
73 views

What is the “main” difference between consensus mechanism of Bitcoin and Ethereum?

Bitcoin and Ethereum both use proof-of-work (PoW) consensus mechanism. One of differences between Bitcoin Pow and Ethereum PoW is difficulty level, meaning that while in bitcoin block generation rate ...
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 ...
173
votes
8answers
106k views

What exactly is Mining?

I have heard that mining is for people with ready hardware and blah blah blah... But what exactly is it? Does it operate like real mining? I mean, people talk about it like you are physically mining.
1
vote
1answer
68 views

Partial Proof of Work in Pools

Technically speaking a full PoW solution is one whose hash value is below a certain threshold value say V. It is not equivalent to saying that the hash value must begin with say X number of zeros (...
2
votes
1answer
51 views

Is this calculation of mining probability using the Bernoulli trial formula accurate?

I'm trying to understand the formulas for successfully mining a block (without a pool) based on hashrate over time (i.e. to chart the probability of finding a block at various historical points ...
3
votes
7answers
330 views

Justification of usage of Blockchain by banks

After learning a bit about Bitcoin and Blockchain Technology, I do not understand how any bank is going to use it. My understanding is that the blockchain is useful in an environment of mistrust. In ...
2
votes
1answer
138 views

Can Bitcoin(PoW) work under partial synchrony?

This paper rigorously proves that Bitcoin can achieve consensus under the assumption of bounded message delivery time: Messages in a mailbox may be delivered in any order, and at any ...
4
votes
1answer
91 views

POW based blockchains systems Majority Attack

TL;DR: With only 30% of network power a Majority Attack is possible and profitable. Am I missing anything? Generally speaking, blockchains based on Proof-of-Work authentications are using amount of ...
2
votes
1answer
56 views

Proof of work: average number of tries to create a block

First, I'm sorry if I'm asking a stupid question. I'm just trying to understand bitcoin. I'm reading the Ethereum white paper, and I couldn't understand this sentence about proof of work: At the ...
8
votes
1answer
1k views

What prevents similar time-warp attacks in Bitcoin as happened to Verge?

Right now (may 2018), Verge (an altcoin with proof of work) was attacked by time-warp attack. More can be read here https://blog.theabacus.io/the-verge-hack-explained-7942f63a3017 What exactly ...
6
votes
1answer
364 views

Is it possible to combine PoW with PoS by taking turns?

I have read about cryptocurrencies and am very excited by many. I have read that one of the worries and constant debates is Proof of Work vs Proof of State with respect to securing the validity of the ...
3
votes
1answer
79 views

Why haven't a large number of cryptocurrencies copied Primecoin's mining algorithm? [closed]

According to my understanding, generating an ever-growing list of prime numbers benefits mathematics and society in some mysterious way. Given this, why have more recently created proof-of-work ...
1
vote
2answers
4k views

altcoin debug.log shows ERROR: CTxDB::LoadBlockIndex() : Failed stake modifier checkpoint height=0

What I have done so far: Generated new Genesis Block Generated new MerkleRoot Updated MerkleRoot Updated Genesis block values Commented out these lines Compiled on CentOS 6 Created altcoin....
1
vote
1answer
130 views

Is “Proof-of-work” a subset of “Byzantine fault tolerance (BFT)”?

Can we say that Proof-of-work is a type of Byzantine fault tolerance (BFT) ? In other words, is PoW a subset of BFT ? Or they are two different categories? Please note that there is a similar ...
0
votes
3answers
49 views

What is resource of mining rewards

How the coins must be paid miners for mining process is provided? One of resources may be transactions fee. Is there any other resources for proving reward of miners?
0
votes
1answer
24 views

How is the amount of proof-of-work invested in a chain calculated?

The bitcoin whitepaper (page 3) states The majority decision is represented by the longest chain, which has the greatest proof-of-work effort invested in it. I could not find how exactly this ...
0
votes
2answers
137 views

Where can i find proof of work in Electrum(light weight bitcoin) source code?

Hi does anyone knows where can i find electrum's proof of work in the source? https://github.com/spesmilo/electrum
18
votes
2answers
11k views

What is proof-of-work?

Please explain the proof-of-work concept. And how does it relate to Bitcoin mining in general, and to the proofs of work (aka shares) of mining pools?
2
votes
3answers
452 views

PoW 51% attack vs. BFT 1/3 attack?

So from what I understand, Bitcoin's PoW is prone to 51% attack, but as a distributed system it is also prone to BFT's 1/3 attack right? I think it's mathematically proven that in a distributed system,...
0
votes
2answers
64 views

What is the reason to pay miners “monetary rewards” for mining process?

Is it correct to say that: In Bitcoin, it is crucial to incentivize miners by monetary reward, because mining process has significant monetary cost (energy/electricity cost). ? otherwise, mining ...
0
votes
2answers
48 views

What would happen if PoW cost were drastically reduced or eliminated?

Assuming Bitcoin had a different method for selecting winning nodes and controlling block time creation, please describe step-by-step how the Bitcoin network would be vulnerable to various attacks. ...
4
votes
2answers
482 views

How does a miner get selected in Proof Of Stake?

I am trying to understand POS. I get that POS uses currency held analogous to the hash power held in POW system. More the stake we have, more are our chances of mining the block. At various sources I ...
0
votes
0answers
26 views

What is the error rate when mining blocks ?

I am doing the Coursera course on Bitcoin and Crypto tech, and there is a formula defined : Goodput = Throughput * Success Rate. 'Throughput' is defined as how quickly we are finding blocks, whilst '...
0
votes
1answer
36 views

Ethereum's PoW difficulty

Bitcoin's block time is about 10 minutes while that of Ethereum is 15 secs. Both are using PoW at this moment, right? How come Ethereum's block time is so short compared to Bitcoin? Is hashing a lot ...
15
votes
6answers
5k views

Why do we need Proof of Work in bitcoin?

I know that proof of work shows that the person has put in some time and power into the processing. I also know that bitcoin mining is adding a transaction into the blockchain and then the miner will ...
2
votes
2answers
56 views

Blockchain validation process is linear?

I've read at a few places that the nodes validate transactions in a linear fashion, i.e. after node A validates, then node B, etc. (which is also the reason, as claimed by many, why blockchain suffers ...
1
vote
1answer
30 views

Security via Proof - of - Work

I am reading Satoshi's original paper, merely for the sake of understanding the concept. I have minimal computer science background (some), mostly just mathematics. In Section 4. Proof of Work of ...