Episode #125 of the Stack Overflow podcast is here. We talk Tilde Club and mechanical keyboards. Listen now

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.

Filter by
Sorted by
Tagged with
1
vote
1answer
730 views

How does the bitcoin transaction fee get paid to miner(s)?

According to https://bitcoinfees.info/ The current "cheap" rate for a bitcoin transaction is $22. How does this get paid to the miners? Is it just one miner that verifies the transaction, puts it ...
1
vote
3answers
69 views

What are the chances that Bitcoin changes its proof-concept one day?

Is it realistic/possible that the bitcoin core team make a new Bitcoin Improvement Proposal (BIP) on day in which they propose to change Proof of Work (POW) with something else (proof of stake for ...
1
vote
1answer
144 views

Blockchain beyond bitcoin etc. - Who is mining?

People are praising the blockchain for use in all kinds of environments where a secure transaction history is required, e.g. logistics etc. My question: Let's say someone sets up a blockchain for ...
1
vote
2answers
281 views

Why don't the miners just take profit from our coins and make the coin worthless?

You own a very valuable thing and you want to go to holiday without it, but there is nobody who you trust and who can look after the thing. So you take somebody unknown to guard it. You pay him a fee ...
1
vote
1answer
280 views

A theoretical low cost attack scenario in PoW currencies

The scenario was designed by user:croraf and me in discussing a question of mine yesterday. To make it more clear, I want to present it here again in a stricter design. To do it in a clear way, first ...
4
votes
3answers
356 views

Egoistic miners combined with large transactions destroy PoW?

EDIT There is a clearer description of some parts of the problem in the link questions. If there is a transaction value much higher than the payment for mining 10 new blocks, how can you trust this ...
1
vote
1answer
617 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
1answer
196 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 ...
0
votes
2answers
143 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
0
votes
2answers
80 views

Review of “equitable” proof-of-work systems

One major criticism against usual SHA-based proof-of-work systems in main cryptocurrencies (except the ecological concerns) is the fact that, years after years, it's more and more dominated by a ...
4
votes
2answers
577 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 ...
1
vote
1answer
63 views

Bitcoin Proof of work puzzle inconsistency

At this time, I am really confused about the Proof of work puzzle because as I have seen in some documents, there are 2 different ways to talk about them. The first one I have seen is from some ...
0
votes
3answers
343 views

After sending/flooding transactions, how do we know that a specific transaction is on all nodes?

In the book "Mastering the Blockchain" by Imran Bashir, it says that a transaction's life cycle is the following: A user/sender sends a transaction using wallet software or some other interface. ...
1
vote
2answers
112 views

How does the network know the legitimate chain in a double-spend attempt?

Apologies if this has been covered, but there's one area of the Bitcoin network that is not clear in my head, and it's intimately linked to the double-spend problem. Suppose Person A is purchasing an ...
1
vote
1answer
132 views

How is mining time validated?

New target is calculated from the T(new_block-1) - T(new_block-2016). Here T is the time miner mined the block. Miner itself sets this time for the block. Thus miner can falsify this time. I see a ...
2
votes
3answers
3k views

How proof of work prevents double spend

One article I am reading said that proof of work system is used in Bitcoin to prevent double spending. More particularly: Imagine we are protecting against double spending in following way. When Bob ...
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
160 views

Creating blocks while more transactions arrive and proof of work mechanics

I am having a hard time understanding the details of how blocks are getting created by miners while many transactions are being received by various nodes at slightly different times and what ...
0
votes
1answer
51 views

Miner modify pending block (not yet on chain) and successfully solve the PoW

For example, I pay a cup of coffee with bitcoin, and later remove that transaction from the pending block that is not yet on chain. After 10 mins, I successfully and luckily solve the PoW problem, and ...
1
vote
2answers
693 views

How many nonces on average do I need to try in order to get n leading zeros?

Assuming 256-bit hash output, how does the (average) number of nonces I need to try (to solve the proof-of-work puzzle) grow with the number of leading zeroes required, n? Is there a bound on this ...
0
votes
1answer
194 views

Hashcash proof of work bitcoin sha256

I'm looking for a program or something to run from the terminal in mac. That does the same thing as the program found here. http://www.blockchain-basics.com/HashPuzzle.html?nonce=221 What I'm looking ...
0
votes
1answer
88 views

How many proof-of-work algorithm exists for crypto currencies?

How many proof-of-work algorithm exists for crypto currencies ? We know PoW in Bitcoin and Etherium are different. Is there any other algorithm used for crypto currencies ?
0
votes
1answer
722 views

Steal proof-of-work answer from a miner [duplicate]

Is it possible to steal proof-of-work answer from a miner who has insecure machine? Consider a miner who has insecure machine found correct answer of proof-of-work and an adversary steals this it and ...
4
votes
1answer
286 views

What is the downside of not using Proof of Work for validator selection?

Bitcoin uses Proof of Work for two things: one is to secure the blockchain with strong cryptographic signatures like a Merkle tree, and the other is to crown the validator which "mines" a solution as ...
0
votes
1answer
377 views

Is there any link between Bitcoin's PoW and BFT?

As per Bitcoin's documentation, the consensus mechanism in Bitcoin Blockchain is based on PoW. Thus, any miner node successfully computing the hash as per difficulty is eligible to mine a block and ...
2
votes
2answers
2k views

Transaction verification vs block mining

I cannot clearly understand if the transaction verification is done over a single or double phase. This is my understanding. Once a transaction is completely assembled, its inputs and outputs ...
0
votes
5answers
169 views

Application of proof of work in bitcoin

Proof of work in spam I understand very well how proof of work is used to prevent email spam for example. Reasoning is since computing the right hash (e.g. with predefined number of zeros for example)...
1
vote
1answer
105 views

Are transactions verified before miner solves the block?

In the PoW mining equation... Hash = (Nonce x prev_hash x list of transactions) the miners find the nonce to add the block to the blockchain and receive the block reward. As we can see, the hash is ...
1
vote
1answer
384 views

Chain with most proof of work - hash target or block header hash?

What is calculated towards the sum of PoW of the chain? Is it the target difficulty that has been met or is it the actual block header hash? Say the target is 000000ABC00000000... and I mine block ...
0
votes
2answers
155 views

How to secure new public proof of work blockchain?

I am fairly new to the bitcoin and blockchain technology and have recently started reading about it. So my understanding and the question bellow may not be very accurate. As I have understood so far, ...
1
vote
1answer
3k views

How much “Proof of work accepted by server” needed to generate 1 bitcoin (or a part of it) [duplicate]

I am using Bitminter client, and I am confusing about how much I earn in one week while my system working overnight. https://bitminter.com/ says "Mining one bitcoin with just a PC now takes millions ...
1
vote
1answer
175 views

How the first succesful miner is ensured his reward

With my still rather limited knowledge of bitcoin, I was wondering how the correct origin of proof of work is ensured. Specifically, when a miner successful computes a valid hash and is to broadcast ...
3
votes
7answers
348 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
114 views

Are the mining incentives of bitcoin compatible with the existence of a competing Proof-of-Work chain? [closed]

Scenario A: A chain split occurs due to a bug or contentious rule change (i.e. the miner incentives aren't changed in any way). Both coins initially start out with the same difficulty (and won't ...
2
votes
1answer
9k views

What happens when there are no Bitcoins miners anymore [duplicate]

So if I'm not wrong, the proof of work is the way to validate all the transactions in a Block. The miner gets (at the moment) 12,5 Bitcoins as a reward for each validated block. So my question is: ...
2
votes
0answers
311 views

Probability of Orphaned Blocks

This is a question regarding the probability of orphaned blocks depending on the block interval. I am using Bitcoin vs Litecoin as an example. Assuming equal hash rate and number of transactions, ...
1
vote
0answers
41 views

What's a good repo to fork if you want to create a blockchain like a “Math” coin or Curecoin. (mining equations, not hashes)

I want to create my own crypto currency and I want to know what's the best github repo to fork when it comes to making a blockchain that's based off of getting the miners to do mathematical ...
2
votes
0answers
115 views

Zero-knowledge/Arthur-Merlin Proof-of-Work for NP-like problems with coin flips hashes of recent transactions [closed]

On a previous answer to a question about making proof-of-work more useful, two challenges were provided: "1. The work must be much, much easier to verify than to do, and 2. The work must in fact ...
2
votes
1answer
432 views

why verification of transaction after proof of work?

I have question about bitcoin protocol. In Satoshi's paper it is mentioned that: New transactions are broadcast to all nodes. Each node collects new transactions into a block. Each node works on ...
1
vote
2answers
102 views

Would an optimization proof-of-work problem where the entity with the lowest hash wins have any security weakness or other disadvantage?

I am wondering if there would be any security deficiencies if cryptocurrencies such as Bitcoin were to change their proof-of-work problems to optimization contests. For example, suppose Bitcoin were ...
1
vote
2answers
1k views

How proof-of-work detects Sybil attack in Bitcoin?

I read in several paper that PoW deters Sybil attack in Bitcoin. However, there is no enough explanation about how proof-of-work detects Sybil attack in Bitcoin?
1
vote
0answers
160 views

Limit of Proof of Work [duplicate]

I do not have a complete understanding of bitcoin, but I feel that the PoW concept will not do it in the long run, so I need you to explain to me if I'm wrong. First of all, all this work force is ...
1
vote
0answers
106 views

What are bitcoin miners actually solving? [duplicate]

I've read all other answer, but nobody really gives an answer. Whom for are they solving, and what entity outside BTC community has benefits from all the electric energy wasted in the process of doing ...
0
votes
1answer
182 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 ...
-1
votes
1answer
110 views

How are miners prevented from doing too much work?

I understand that scripts can be written within transactions that make the miners do some work. How does Bitcoin ensure that scripts that make miners do too much work are prevented?
17
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 ...
0
votes
1answer
63 views

Proof of work: optimal number of transactions?

I've been struggling with this Q for a while: My initial understanding was that miners start to work on PoW for new block immediately after the previous round's block is confirmed. My Q is this: ...
9
votes
3answers
6k views

How does Proof of Burn work?

I have been trying to make a comparison between PoW, PoS and Proof of Burn. While I understood the other two, I want to know how exactly Proof of Burn helps in attaining the consensus. One burns ...
1
vote
1answer
186 views

Does 4 byte Nonce enough to proof of work?

Is it always possible to find an hash value of a block, smaller than the current difficulty, just using 4 byte (Nonce) ? How can we be sure about it ?
1
vote
1answer
281 views

The 51% assumption

I am new to understanding how bitcoin works but reading up a little on PoS and PoW, I understand that anyone with over 50% of the network resources (bitcoins or computing power respectively) can ...