Questions tagged [proof-of-work]
A proof-of-work (POW) system is an economic measure to deter denial of service attacks and other service abuses such as spam on a network by requiring some work from the service requester, usually meaning processing time by a computer.
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Calculating difficulty and target with 256 bits
Why do the yellow paper and Ethereum implementations use 2**256 instead of 2**256 - 1 when calculating hash target from difficulty?
The Ethereum Yellow Paper uses 2**256 / difficulty to define the ...
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make a new PoS blockchain with geth (go-ethereum)
many tutorials out there tell how to create personal PoA or PoW chain with go-ethereum(geth), how to create a PoS based blockchain with go-ethereum ?
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Why do we still pay gas in proof-of-stake?
When Ethereum was on a proof-of-work business model, gas had to be paid to miners to execute transactions. Now that the miners are gone in the new proof-of-stake system, why are we still paying gas on ...
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How to create Proof of Stake node?
I need to create a Proof of Stake node Ethereum but I'm not be able to find the solution.
I know how to create PoA and PoW networks but have no idea about PoS.
e.g to create a PoA network we need to ...
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Verifying Transactions before Finding Nonce
I am trying to learn theoretical fundamentals of Blockchain.
In PoW, the miner who finds the nonce first gets to create next block and all other nodes add that block.
Now, what I don't understand ...
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Is it possible to independently validate the whole chain in the ethereum?
In PoW system, a node can trustlessly check for validity of the whole chain just by checking the hash of every block correspond to the prev hash in the descendant block header. As far as I know in the ...
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How does Difficulty Bomb (DB) help transition to Proof of Stake (POS) if miners can just fork and remove it?
I understand that DB is introduced to incentivise miners to transition to POS since mining would become impossible after certain point under POW. But since miners could just fork and remove it, why ...
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Why is the block limit so low?
The Ethereum block limit is currently 30M gas. From what I have read elsewhere, this limit has been ostensibly chosen so as to ensure that processing transactions remains feasible for consumer grade ...
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Transaction order in Ethereum Proof of Work
My Question is:
How does picking and ordering transactions connect to Proof of Work Consensus
Let me explain a little bit more:
I'm confused about a concept in Proof of Work (PoW) on Ethereum.
I ...
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How can a smart contract deployed on Mainnet know if it is running on PoW or (in the future) PoS?
I'd like my smart contract to know if it's running on PoW or (in the future) PoS in Mainnet. Does checking for block.difficulty solve the problem?
If so, what will be the value of block.difficulty ...
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What is the incentive for people running execution clients in eth2
If I understand correctly, in the coming proof of stake version of Ethereum, there would be the beacon chain, with blocks on it created by validators. These validators will get compensated for doing ...
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publishing blocks with delay
this is rather a simple and fundamental question but nevertheless i couldn't find any solution for it and now I'm worried if it can cause real attacks to slow blockchains.
imagine in a form of ...
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What controls the inter-block interval in proof-of-stake?
In proof-of-work, the interval between 2 blocks is controlled by the mining difficulty: in Bitcoin, at all times, it must take roughly 10 minutes to mine a block, so every two weeks we adjust the ...
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High Block Validation
Suppose node A is running on height 2000. Node B sends to node A block with height 2002. Node A is not able to validate the block without having a block with height 2001. How does node A behave in ...
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How to reverse engineer ETH POW
If I store 10 blocks from Ethereum, with the block difficulty, mixHash and nonce etc. Transactions etc. Is it possible for me to back trace that the information I have stored is actually correct and ...
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Does a Proof of Authority network consume much less energy than a PoW/PoS one?
One of the main problems of PoW networks like Bitcoin or Ethereum is its energy consumption.
Question 1: does this get solved with PoA networks?(without taking in account that these are not really ...
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Is there a mistake in this passage about the requirements on the block header nonce?
It says that PoW evaluates to an array with the first item being the mix-hash, and the second item being a pseudo-random number. However, from equation 49, it would seem it is the second item, m, ...
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Even if I own 51% of stake (or have 51% computational power) and try to cheat, can't others still see that my block is invalid?
I'm thinking about how proof of stake works exactly.
As I understand, here is how it is secure:
I cannot forge a tx where random A pays me X amount because I would need the private keys of A. ...
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Ethereum2.0 Shard chains will be PoW or PoS
I'm sorry if this is a basic question. But will the new shard chains for Ethereum2.0 be PoW or PoS?
I know the plan is for Eth1 mainnet to "dock" onto the beacon chain eventually and be its ...
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Why don't blockchains use simple voting based consensus algorithms?
Suppose we have an malicious agent Bob with account balance of 100 units trying to double spend a coin by broadcasting two messages simultaneously:
A: Bob sends Alice 100 units
B: Bob sends Emily 100 ...
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How are difficulty of finding a proof of work dynamically regulated without a central body? [duplicate]
The probability of a miners to mine a block dynamically changes so that blocks are mined at regular intervals.How does block chains accomplish this without a central regulating body,
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“Universal Proof of Work” with SNARKs?
If SNARKs are able to prove computations of arbitrary complexity and difficulty were executed correctly, would it be possible to use them to create a Proof of Work system where ANY computation can be ...
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Ethereum vs bitcoin technology [closed]
I have understood how bitcoin works (coinbase block, mining, links between transactions, hashrate, nounce, proof of work, ...)
Now i want to understand how Ethereum works.
Can we say it is the same ...
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When an Ethereum transaction event occurs, is there a case when it was not included in the main chain later due to a fork?
I know Ethereum is a POW blockchain where forks take place.
The transaction event is issued after executing the transaction on the node. If a fork occurs, is there a possibility that the transaction ...
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Does successful mining require the block's transactions in advance?
Typically a miner decides which transactions go inside a block. But does this have to be so? Is the actual mining process just a process to find the right nonce regardless of block contents or does it ...
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What if difficulty exceeds the length of a fixed sha256 hash in proof of work?
Hello im a newbie in Blockchain, i got to know some basics, but im confused that what if the difficulty exceeds the length of a sha256 fixed length string
example :
The fixed length is here 64 (sha256)...
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Is Ethereum 2.0 (Sharding Ethereum) only PoS based? Or a combination of PoW + PoS?
Does Ethereum 2.0 (Sharded Ethereum) only use PoS (Proof-of-stake) for consensus mechanism ?
Or
Does it use a combination of PoW + PoS ?
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Why does proof of work targeted zeros always comes at the start of hash? why is it not in the middle or the end of hash?
My question is why always targeted zeros come at the start of hash of the block? I have never seen more than 2 zeros in middle or somewhere else in the hash of mined block... What's the reason?....
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Resources of a miner's reward in Ethereum?
To compensate the miner who could solve the PoW as the first one, they will receive some coins as a reward for keeping them motivated due to the costs related to mining process (electricity and ...
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how transaction in block-chain is validated
Please explain complete procedure/journey how transaction in block-chain get validated by miners, From broadcast of transaction to become part of new block.
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PoW in Public blockchain Vs. PoW in Private blockchain
I am reading about consensus mechanisms in blockchain and it is stated that PoW (Proof of Work) requires longer confirmation time compared with voting-based mechanisms. But some things are not clear ...
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Why is PoW needed to confirm transactions and add new blocks [closed]
I have read and I vaguely understand about how Proof of Work works and what does it do. But why PoW?
Or more bluntly, why do we need any algorithm at all to add new blocks.
What would happen if ...
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What should I prepare for the coming ETH 2.0 upgrade as a Dapps developer?
As announced, Ethereum is expected to be its upgraded version Eth2.0 probably from 2020. There will be several upgrades like
PoW to PoS/Casper FFG
eWasm integration
sharding (Casper CBC)
These ...
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Why 51% hash power require to control the network?
Why 51% is explicitly mentioned to get control over the network?. Why not 50 or lesser ?. Anyway there is no central authority to decide, whether 51% is attained or not?.
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When is a new block created?
I am currently reading an interesting book about solidity, and I'm reading about block creation. This gives a good overview:
The book mentions that the maximum size of a block is determined by the ...
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Does the ETH blockchain have fundamentally more branching than BTC?
Intuitively speaking, ETH seemed to have simply increased the average block generation rate from one every 10 min in BTC to 1 every 15 seconds. There doesn't seem to be any other protection against ...
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How to make atomic swap between Ethereum and POS chain?
There's simple way to make atomic swap for smart-contact chain and any POW chain.
For example for Ether <> BTC:
Alice sends some Ether to the swap smart-contact which locks this money. While ...
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How are transactions ordered in POS?
With POW, the miners who finds the block chooses the order of transactions in that block. How will this work with POS?
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How does the network validate a block in PoS
In general PoS, the forgers stake their coins and then a validator chosen in a pseudorandom fashion gets the chance to validate a block. But how do the whole network validate it?
In PoW, for example, ...
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How feasible it to combine Proof of Work and Proof of Elapsed time consensus to create a custom blockchain?
I wonder if it feasible to create your own custom consensus by combining Proof of Work and Proof of Elapsed time?
How would I approach it? Any tools or frameworks to build it?
I appreciate all the ...
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Deliberate Slashing: Don't slashing and leaking incentivize DDOS attacks on smaller nodes? Won't this centralize POS more than POW, even?
In Ethereum's proposed proof-of-stake algorithm (POS):
A traditional node operator can't host a node themselves (e.g. on a home network), someone could just DDOS their node to bring them offline. ...
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Who generates the mathematical problem for miners?
In POW miners solve an problem for successfully mining a block, who provide the question to the miners ?, does all miners work on same problem ?, and how the miners verify the answer ?, if the problem ...
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Can't we incentivize miners to include more transactions in their block?
If you go to etherscan.io, you can see that each block has the different number of transactions. Can't we incentivize miners(e.g. give more rewards ) to include more transactions in their block so ...
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what does memory hard mean in ETH POW? [duplicate]
I came across the term memory-hard while ready about ETH POW algorithm. What does it mean when someone says that POW is memory hard?
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Transaction throughput: POA vs POW in private blockchain networks
I know that proof of work is resource intensive, while proof of authority is much faster as no consensus is required since the network is validated by the proper authorities.
But in terms of the ...
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how to setup hybrid PoW+PoS or PoA private network (geth)
I am aware about PoW and PoA setups of ethereum private networks but would like to know if anyone could help or point me the direction how to build a hybrid PoW + PoS or PoW + PoA ethereum based ...
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Nonce in proof of work
When a block is being mined nonce will be generated so that the nonce is appended with the previous block hash,data. Then the resulting hash of that appended value should be less than the target.
The ...
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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 ...
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I don't really understand how mining works, anyone can help?
I am currently studying Ethereum all by myself, and am struggling to understand how mining and Proof of work work.
I have read many posts and books about it but still hard to understand how the ...
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During the POW/POS transition, why would a POW miner choose to mine on the chain with the POS consensus algorithm?
As the title says, what incentive does a POW miner have to mine on the hybrid POS chain? They would, effectively, be removing their own economic incentive from the consensus mechanism. I understand ...
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