Homework on Mining and Proof of Work - Questions

[Nedu]

1. It is important to make miners spend money on electricity so that they may want to recoup them.

2. Because they will loose money and because the longest chain is accepted and it will be practically impossible to change a previously added block and to over-run the blocks of the honest guys.

3.It regulates the mining difficulty by making the target low when the difficulty is high or when there are many miners.

[Slavy]

1. Because of incentives
2. They have to mine much faster
3. By using target the hash number is less than the target, that block is accepted by the network. The more miners, the lower target, the more difficult to guess the nonce.

[56butch]

1. Spending money (electricity) on mining gives miners an
   incentive to reap block rewards and transaction fees.

2. The cryptographic puzzle is based on the content of the previous block,
   If a miner tried to change or remove a transaction from a previous block
   or any block in the chain, the link will be broken. And the miner will have to
   recreate all of the links.

3. There is a random number, the nonce, miners have to guess. The nonce
   together with the transaction list, previous hash and the miner’s hash has to
   be less than a so called target number. And the target number ranges from
   zero to infinity. The more miners there are on the network, the lower the
   target will be. This makes it more difficult to guess the target.

[abelhingle]

1
Its important for miners to spend on electricity for one so that thew will loose money for trying to add a bad block and also so that they will try to get the correct nonce as hard as they can so they can make their electricity back!

2
the system only accepts the longest chain of blocks. you would never catch up with the current length of blocks.

3
The more miners there are the lower the random number is there for makes is harder to guess a correct nonce.

[Clint_Oka]

yeee best answer I saw!!!

[Yann]

1. Why is it important to make sure that miners spend money (on electricity) while mining? Cost of electricity is the investment miners do in order to get rewarded (profits if you like). If they do not follow the rules the ‘loose’ their investment.
2. Why would it be very difficult for someone to go back change a previously added block? It is practically impossible because it would require for the full network to redo all the blocks starting from the one that is changed. Changing a previous blocks changes all the blocks after that block.
3. How does the network regulate mining difficulty? When there are more miners competing for the block the difficulty (of the nonce) is increased. This means the target is lowered, which requires the ‘guess’ to be closer to the truth.

[Nate]

1. Buy Spending money on electricity the miner are more likely to follow the rules.
2. Changing any thing on the block will change the hash witch would break the link to the next block so every block would have to be re mined witch would take to long.
3. The more miners the harder it is to guess the nonce because the target has been lowerd.

[RayUtik]

1. They all competing with each other. To get a block rewards they have to solve puzzles and spend a lot of electricity on that. If they do smith wrong or cheat then they won’t get rewards but spend money on electricity only.
2. Because there will be a thousand more of new blocks. To correct (re mine) each one will take an impossible amount of time for 1 person to to that.
3. By target. It is low when difficulty is high.

[Lena_Ghuraibi]

1. spending money and electricity shows proof of work and also keeps miners incentivized to keep going because they’re earning money by mining with following the rules.

2. because the previous hash will change therefore all the blocks that come after the altered block will not work because every block is dependent on the hash of the block before it, so to get it back, you’ll have to guess the nonce of each block all over again.

3. when the number of miners increases, the target number decreases, therefore difficulty increases because the hash must be between 0 and the target number, so when the target number decreases, only a small percentage of the hashes will be accepted.

[Kaiulan]

1. to make their loss from electricity even and even get kore return to earn money and make it all worth while.
2. because it will change all the hashes from every block in the chain as they are always a unique fingerprint and they would have to remine it all again which would cost much kore than just mine a new block.
3. the more miner there are the more the difficulty lvl goes up and the more times the nonce has to be guessed.

[Hanibal]

1. Miners have to have an incentive. You need them to spend money so if they try to cheat the system, like trying to double spend, for example, the other nodes in the system will find out right away that the hash is wrong and not put it in the chain, if it isn’t but in the chain, you don’t get the block reward nor the transaction fee. So you only spend a lot of money on electricity. With no profit.

2. Theoretically it is possible, but practically it is not because you would need to hash out every single block which comes after that too, once any transaction in a block gets changed, the whole hash changes. If the hash changes, the hash of the block after that changes too because it is also based on the hash of the previous bock. And so on and so on. You would have to have at least 51% of the whole Mining power to accomplish that, which in it self would be impossible. But even if you had that. Just mining alone with that power would make you more money.

3. The more people are mining the more difficult it is to find the correct hash. Because your hash has to be under a specific target range. If more people mine the target range gets lower/smaller. Which makes it easier for you to randomly generate a hash which is above the specific range. If that happens you have to try again and again and again. Until you generated a hash under the target range.

[MKrag]

1. It is important for miners to spend resources while mining so that trying to hack the blockchain is not worth it in comparison to just abiding by the rules and helping build the blockchain instead.

2. It is very difficult for someone to change a block because it would mean that he would have to out-hash the whole bitcoin network to legitimize the altered block, by making a blockchain longer than the one proposed by the rest of the network. It is practically impossible to perform such a feat, especially on one machine.

3. The network regulates mining difficulty in accordance with how many miners there are at any one given time. If the number of miners suddenly drops, the network will make the acceptable answer easier to compensate in the time needed to solve the function. If the number of miners increases, mining will become more difficult.

[akshaykh1]

• Why is it important to make sure that miners spend money (on electricity) while mining?
  It ensures that miners have an incentive to mine ethically and not indulge in manipulation for blockchain.
• Why would it be very difficult for someone to go back change a previously added block? It would be very difficult to change the previously added block because in order to change the previously added block the miner would have to recalculate the hash rate for all the previous blocks which would be time-consuming and nearly impossible as anything changed in the previous block will break the link for all the other blocks meanwhile new blocks are being added.
• How does the network regulate mining difficulty?
  Network regulates the mining difficulty by ensuring the target is less than the hash rate and if there are more miners the target rate is lower making it more difficult to guess the nonce,

[Attiss]

1. Why is it important to make sure that miners spend money (on electricity) while mining?
   It’s all about incentives. The miner must risk something (money on electricity) in order to potentially earn the Block Reward and Transaction Fees. Since cheating the system is extremely difficult, it’s more risky (less profitable) for miners to cheat than to play by the rules.

2. Why would it be very difficult for someone to go back change a previously added block?
   Changing a previous block will invalidate the hash of subsequent blocks. It would require them changing a huge amount of hash functions in order to catch up to the longest chain and have their change accepted into the blockchain.

3. How does the network regulate mining difficulty?
   When there are more miners, the target is lower and therefore the nonce is harder to guess.

[AverageJoe]

1. So that it incentivises them to follow the rules of the network. Proof of work.

2. Because it would invalidate all other transactions since the transaction that had been changed, meaning all of those transactions would have to be remined into new blocks. You would have to do this and then catch up with and overtake the current version of the blockchain to then validate the change you made. this is practically impossible, and you would earn more money just by following the rules of the network and using that computing power to mine current blocks.

3. The network regulates block difficulty by seeing how much time blocks are being solved/validated in and adjusting the difficulty for the upcoming blocks by changing the value of the nonce. If the blocks are being validated to quickly, the network will increase the difficulty by lowering the nonce and vice-versa.

[BlackPearl]

1. They have first to invest (spend money) on electricity and then get the reward to play by the rules. If they cheat they don’t get a reward but only lose money
2. Because it doesn’t make sense… He must be very fast and use a lot of more energy to catch up the other miners. New blocks are added and he has to change them also. It doesnt make any sense. Is it better to use this power and play by the rules
3. If the difficulty grows (more miners are mining) the target gets lower. It is difficult to gues the nounce

[Ayajib]

1. It is important because miners also need to invest something in order for them to be responsible for the network. If they don’t spend money on electricity there is no incentive for them to mine correctly.

2. I would be very difficult to change a previously added block because it would change all the outputs in all the next blocks created after that and also it would require consensus of all the miners in the network.

3. The network difficulty is regulated by decreasing the possible output of the hash functions. Miners have the guess a no. called nonce which can range from 0 to infinity, More miners means lower the nonce and harder it is to guess the no, Nonce also fluctuates every 10 mins according to the no. of miners.

[Gulaman]

Homework on Mining and Proof of Work - Questions

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

2. Why would it be very difficult for someone to go back change a previously added block?
   Block contains reference hash from previous block

3. How does the network regulate mining difficulty?
   More miners = lower target set = higher difficulty

[MichaelW]

1. Why is it important to make sure that miners spend money (on electricity) while mining?
   To make sure they are being honest
2. Why would it be very difficult for someone to go back change a previously added block?
   They have to mine two blocks faster than everyone else mines 1
3. How does the network regulate mining difficulty?
   The protocol lowers and raises the difficultly to keep blocks as close to 10 mins apart as possible.

[GoldenMantis]

1. By making miners pay for electricity consumption, they are incentivized to make sure that energy consumption isn’t being wasted on bad transactions.
2. All of the hashes must match going forward, which is practically impossible.
3. Difficulty is increased based on increased hashrate.