Homework on Mining and Proof of Work - Questions

Blockchain and Bitcoin 101
#4560
  1. By spending money the miners have incentives to follow the rules since they are invested in the mining process.
  2. If anything is changed in the previous block it would break the link to the next and the following blocks.
  3. As there are more miners the difficulty to guess the nonce is increased by lowering the target.
1 Like
#4561

  1. it is important that miners spend money so that they are incentivized to regain their lost funds and make money the only way to do this is by playing by the rules to achieve the goal of the blockchain.

  2. this would be very difficult because they would have to not only hash that one block but every block attached to it. this because it would not match the other hashes. this would be impossible for one miner to do by itself. it would take thousands of years. \

  3. the network regulates difficulty by lowering the target to make it harder to find the nonce. this all happens when there are more miners

1 Like
#4562
  1. It is essentially where PoW comes into play. Their efforts in expending time and electricity to solve the puzzle becomes proof of their financial commitment to verifying the blockchain. It in turn validates the need for incentivization that comes rewarding the node with the correct answer with the BlockReward and revenue from transactional fees to recuperate their losses and turn a profit.
  2. It would be difficult because the blockchain is itself a foundational structure, in that it relies on the hashes from previous blocks to be built. If any of information within the previous blocks gets changed then the entire blockchain up to the current time has to be revalidated to reflect the new changes and that would require an enormous amount of hashpower and time to redo; not to mention the financial toll it would take for any one node to do that alone. You would require 51% of the hashpower alone just to be able to pull off such a feat, not that there’s any real financial gain in doing so.
  3. The network regulates mining difficulty by changing the target number. The lower the target, the higher the mining difficulty. Because of the unpredictability of the hash function, miners have to constantly plug in different nonces to guess the right hash that would fall below the target number. There is no easy way to logically guess the right nonce; only by brute force until the hash is below the target. Depending on the number of miners involved in validating a certain block, the mining difficulty can be adjusted accordingly.
1 Like
#4563

  1. Why is it important to make sure that miners spend money (on electricity) while mining?
    Provides incentives for the miners so they follow the rules.

  2. Why would it be very difficult for someone to go back change a previously added block?
    Because the hash changes and it breaks all previous blocks causing them to have to remine all previous.

  3. How does the network regulate mining difficulty?
    As more miners come about the difficulty rises to guses the nonce by lowering the target.

1 Like
#4564

  1. Why is it important to make sure that miners spend money (on electricity) while mining?
    This is how the miners are incentivized to respect the rules, if they don`t, their blocks will not be confirmed and they lose the money spent on electricity.

  2. Why would it be very difficult for someone to go back change a previously added block?
    All blocks are linked between them through the hash function, any data changed in a previous block will change the hash of all blocks that follows it. It is practically impossible for a miner to remine all blocks and continue to add more blocks to the chain before the rest of the miners.

  3. How does the network regulate mining difficulty?
    By changing the target number, the lower the target, the more difficult it is to guess the nonce and the more resources it takes.

1 Like
#4565

basically keeping miners honest. Miners are investing money ( i.e electricty costs ) to recieve payment ( incentives) in return. If miners do not follow the rules it will cost them money ( electricty costs ) and will have no return.

it would takle to long to go back and change previous block. While they are trying to go back and alter data other miners are moving ahead creating blocks and getting rewards

by having it so blocks are mined approximately every 10 minutes

1 Like
#4566
  1. It is important for the miners to spend money because in order to turn a profit from mining they must follow the rules and validate legitimacy to earn money.
  2. In order for someone to go back and change a block they would have to then correct every block following the changed block. Meanwhile, blocks are being added by other nodes making it nearly impossible to catch back up and validate that change in the chain.
  3. The difficulty of the puzzle is based on the hash rate of the network. Miners need to create a hash that is less than the target. The target is a number that depends on the difficulty of the bitcoin network. The more miners on the network, the lower the target will be, making it more difficult for the miners to guess the nonce.
1 Like
#4567

  1. It is important to make sure miners spend money on electricity for mining because it forces them to have some skin in the game prior to participating in the process.

  2. Due to each block having a specifically assigned hash compiled from the data in side the block and previous blocks, if a previous block’s data is changed… then that compromises the entire chain.

  3. The network forces some transactions to be more difficult than others by making the target hash in a very confined zone or a large zone depending on the numbers of users on the network.

1 Like
#4568

1 - So they are incentivized to recoup their money and then make money to profit.

2 - Because they would have to re-mine that block and every block after it. They would need to catch up to the current block in order to make the change.

3 - If there are a high amount of miners then the network will make it harder to guess the nonce by making the target low.

1 Like
#4569
  1. Why is it important to make sure that miners spend money (on electricity) while mining?

So that all incentives are aligned and that they have skin in the game (play by the rules). By making them spend money up front, we prevent miners from doing something malicious to new or previous blocks, which in turn secures the network.

  1. Why would it be very difficult for someone to go back change a previously added block?

Because then they have to remine all the next blocks, while at the same time catch up to the other blocks that continue to get mined. This costs so much money and capital that it’s practically impossible and also makes no sense since miners will only lose money.

  1. How does the network regulate mining difficulty?

The higher the hash rate, the more difficult it becomes to guess the nonce (target is lowered).

1 Like
#4570

Q1. Why is it important to make sure that miners spend money (on electricity) while mining?
A. It is important that miners have an initial outlay so that they are motivated to cover costs and seek profit by following the protocol and helping to secure the blockchain.

Q2. Why would it be very difficult for someone to go back change a previously added block?
A. Each validated block is digitally ‘signed’ by a hash derived from data that includes the hash of the preceding block. Altering the data in any one block, therefore, would alter the hashes of all subsequent blocks in the entire blockchain. This ensures that the blockchain is virtually immutable in the sense that data once entered cannot be removed.

Q3. How does the network regulate mining difficulty?
A. The blockchain network functions by presenting miners with increasingly difficult mathematical ‘puzzles’ when the total mining activity rises, and simpler puzzles when the mining activity (hash rate) falls. This ensures that blocks are mined at a stable, consistent rate - for Bitcoin, one block every ten minutes.

1 Like
#4571

Homework on Mining and Proof of Work - Questions

  1. Why is it important to make sure that miners spend money (on electricity) while mining?

Electricity is like the collateral involved when mining without that collateral you would be looking at no incentives to mine and to make money which comes first before the block reward if there was no electricity involved you would be looking at miners who’s primary goal would be to sabotage the entire network making the network insecure.

  1. Why would it be very difficult for someone to go back change a previously added block?
    Because if you select a block to change data you need to make adjustments re-mine the next blocks involved too because the network would not accept the rest of the blocks due to change and as a result of that you’d be further back from the next blocks and that won’t be accepted within the network thats why data once entered and verified cannot be modified and the network would only accept the longest blocks in the chain thats been already verified because it believes that it look more proof of work to verify those transactions.

  2. How does the network regulate mining difficulty?

The network regulates mining difficulty depending on how many miners are actually in the network if a lot of miners are there the Nonce and Hash guessing procedure becomes at a lower target and the lower the target the more difficult it is to actually guess the nonce and hash

1 Like
#4572
  1. so they have to follow the rules to get rewarded to gain profit.
    2.because it would change the previous hash of the next block changing all the blocks previous hash.
    3.the more minors the more difficult.
1 Like
#4573

1. Why is it important to make sure that miners spend money (on electricity) while mining?
Because if it’s too easy (in the way that they don’t spend money in the process), they don’t risk anything so they could just mine fraudulent transactions (electricity consumption is somehow what they stake)
2. Why would it be very difficult for someone to go back change a previously added block?
Because they’d need 51% of the total computing power to be able to confirm blocks quicker than the rest and therefore get a longer chain, the longest chain, and consequently the one taken as real.
3. How does the network regulate mining difficulty?
They try to keep the block time at about 10 mins and once in a while (every 2 weeks I believe) they check the average block time, if it’s too quick they will increase the difficulty by lowering the target, otherwise they will increase it. I think currently the target is something like the first 17 digits must be 0s (so it’s very low).

1 Like
#4574

  1. It’s because with them spending so much on electricity, it gives even more of an incentive to make sure their blocks are correct. If their blocks are incorrect, they have to spend money on electricity with no profit. But, if their blocks are correct, they have a chance to make money and pay for the electricity fees.

  2. Because the blocks contain so much data, that it would taker them years just to complete one by themselves. Additionally, with most miners wanting to make money, the more accurate and longer blockchains always win. No one is going to wait for a corrected blockchain in order to do business on it.

  3. The more miners that are active on the network, the lower the target and the more difficult mining becomes. Mainly because, if several miners decide to stop mining, the target increases, which makes more miners want to become active to make a larger profit.

1 Like
#4575

1 - Is needed because is a way ensure is going to follow the rules of the PoW, if the miner not follow the rules the transactions not works and the miner need to pay the electricity equals, is more profitable follow the rules :slight_smile:

2 - This is interesting because when you change the values of one block all the hash of blocks change at the same time, in theory is hackable but in practice with the power of computations right now that cant be possible, because you have much things to do, for example : in the most positive scene you has the power of the computer to change the change the hashed , but you still have the upcoming transaction time problems ( every new transactions in new blocks ) so you need to be more fast before a new block mined, in theory is possible but in practice you cant, may be in the future when every one has a quantum computer in the home, but thinking in deep before that happens may be all the hashed are right now gonna be changed and new types of hashed comes based in quantum computers, in the end of the day can be the same only with different computational power

3 - This is interesting too, the difficult of the blockchain ( may be all the blockchains ) is based in hashes, what this means ? when new block is mined that block hash is based in the values of previous block, this and may be more values like timestamp or things like that ( this can be relative i thing, because not all the blockchains are the same ) finished in the result of new hash and this hash is random so the miners dont know the answer before mine, so the “puzzle” ( brute force ) need to be solved to check what is the right answer ( nonce ), so that is the difficulty and if the network needs more difficult may be need too update the pattern and if i dont forget in the bitcoin blockchain are the “0” in front the hash, so it you see "00"XXXXX thats gonna be more easy to solve then "0000000000"XXXXXX, and equals is relative because if you has lucky you can finded in the first iteration, but is difficult if has more 00 in the front, here an example of a code in javascript that i finded ( may be this code explain more clear than me ) :

mineBlock(difficulty) {
  // Keep changing the nonce until the hash of our block starts with enough zero's.
  while (this.hash.substring(0, difficulty) !== Array(difficulty + 1).join("0")) {
    this.nonce++;
    this.hash = this.calculateHash();
  }
    
  console.log("BLOCK MINED: " + this.hash);
}

i spamed a lot, sorry :slight_smile: :heart: ( i keep practice my english )

1 Like
#4576
  1. So they are incentive to make back there capital through block rewards and fees.
  2. Because it would break all the links in the blockchain and they would have to re mine all the new block ahead of it.
  3. they lower the nonce target which makes it more difficult to guess.
1 Like
#4577

  1. Why is it important to make sure that miners spend money (on electricity) while mining?
    Miners are incentivized to append their block to the blockchain. If their block includes errors then it will not be accepted and the miner loses money due to the electricity costs from running their machines.

  2. Why would it be very difficult for someone to go back change a previously added block?
    The blocks in a blockchain are all connected to each other, when a miner wants to add to the blockchain they have to solve a cryptographic puzzle that is based on the contents of previous blocks. So if anyone were to change a transaction in a previously confirmed block, it would break the link to the next block and all blocks after. The miner trying to edit the transaction would then have to re-mine all the blocks. This is impossible because of the hash rate and because the network always chooses the longest chain.

  3. How does the network regulate mining difficulty? the more miners on the network the lower the target hash will need to be.

2 Likes
#4578
  1. Its incentive to play by the rules. No cheating.
  2. Changing the previous blocks will change the hash for all blocks, therefore those blocks would need to be re- mined as well as catch up to new blocks being mined. Very expensive and time consuming.
  3. If there is a lot of miners the targets will be set lower, which makes the difficulty higher.
1 Like
#4579

1 So that they are invested and play by the rules.
2 One block is link to the next so it would throw them all out of whack if you change anything.
3 The more miners the lower the target making it more difficult to guess the nonce.

1 Like