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Why is it important to make sure that miners spend money (on electricity) while mining?
When the miners spend money they have interest in the blockchain. When they cheat they lose money on electricity, while when they are playing by the rules this does not apply. -
Why would it be very difficult for someone to go back change a previously added block?
Because they need to change all the blocks after the transaction in that desired block and they need to keep up with generating new blocks. So you get two chains and it is difficult to maintain one chain by yourself, while still being trustworthy -
How does the network regulate mining difficulty?
It regulates so that every block is mined approximately every 10 minutes
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- By spending money the miners have incentives to follow the rules since they are invested in the mining process.
- If anything is changed in the previous block it would break the link to the next and the following blocks.
- As there are more miners the difficulty to guess the nonce is increased by lowering the target.
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- When miners spend money on electricity they are playing by the rules which secures the network. when you play by the rules you get incentivized (earn $/BTC).
- To go back and change a previous block would require that all subsequent links and blocks would need to be changed. this task would cost too much money and take too much time.
- by forcing the miners to solve the puzzle for each block.
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1. Why is it important to make sure that miners spend money (on electricity) while mining?
to discourage miners from trying to cheat the system
2. Why would it be very difficult for someone to go back change a previously added block?
Because each block hash is linked with the previous and the following block hash. So if we modify a previously added block, we need to recalculate no only the block hash, but also all the hashes of the following blocks.
3. How does the network regulate mining difficulty?
Through the target. That is a previously fixed number that need to be higher than the new hash. If the global computer power used for mining increase the target decrease making the difficulty increase, and viceversa.
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To incentivise them to be honest and not cheating in the newtwork.
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As a Block contains hash from previous block, changing one will change in sequence all the next ones.
3.More miners in the network , the lower the target is set. Lower target means higher difficulty.
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By making sure miners spend money on electricity, gives them an incentivize to play by the rules or risk suffering unnecessary loss. If there was no ābarrier to entryā for miners, it would allow people to mess with the network, or try to at no costā¦ By adding some form of barrier to entry, you leave miner wanting to break even and make profit, as opposed to spend time trying to maliciously profit from the network.
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Why would it be very difficult for someone to go back change a previously added block?
To go back and change a previous block would not help, a user would have to work extra hard and fast to change every block that comes after it, including those that are being newly mined every 10 minutesā¦ It is nonsensical to attempt this as it is practically impossible. -
How does the network regulate mining difficulty?
Blocks are always mined in as near as a 10 minute interval as possible, this means that instead of having a block mined in 5 minutes when there is 2 x the amount of miners, the network increases block difficulty to increase the time needed for it to take to mine a block.
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Questions:
. This is so that miners can play their part in the Blockchain network by trying to solve cryptographic problems so that transactions may occur successfully. They have an incentive to follow the rules as it is the only way which they can make money.
. If one block is changed then all of the other blocks will be altered automatically.
. The block reward decreases as inflation decreases over time and the difficulty will increases as the number of active miners increases. The nonce becomes easier to guess as the target number increases.
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- Why is it important to make sure that miners spend money (on electricity) while mining?
They would lose money if they are dishonest
- Why would it be very difficult for someone to go back and change a previously added block?
All of the blocks are related, so if they change one block they would have to go back and re-mine all the prior blocks. Meanwhile other miners are adding new blocks. This makes it nearly impossible.
- How does the network regulate mining difficulty?
The more miners the higher the difficulty (higher hashing rate = lower target). The fewer miners the easier (lower hashing rate = higher target)
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Why is it important to make sure that miners spend money (on electricity) while mining?
The high cost of mining makes it hard to amass enough mining power to successfully attack or control the history of the chain. It makes mining properly far more likely to be profitable than attempting an attack. -
Why would it be very difficult for someone to go back change a previously added block?
Because a change to a block changes its hash, which in turn changes the hash of every block after it. In order for the network to accept the modified chain every block after the change would need to be re-mined. But the rest of the network will continue adding onto the original chain never giving the modified chain a chance catch up and take over. -
How does the network regulate mining difficulty?
Difficulty is regulated by changing the target for the block hash, setting the maximum number lower to make it more difficult.
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- Important for miners to spend on electricity so they are incentivized to get the reward blocks and fees to cover their costs.
- It would be difficult to go back and change a previous block because they would then have to solve the puzzle for the following blocks and catch up. Very time consuming.
- The network regulates mining difficulty by lowering the target. When the target is low mining becomes more difficult.
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- Why is it important to make sure that miners spend money (on electricity) while mining?
this ensures that miners are playing by the rules because if they donāt play by the rules then the network will reject their work and the money spent on electricity is wasted - Why would it be very difficult for someone to go back change a previously added block?
Because a change in a previous block would invalidate all blocks that come after it. - How does the network regulate mining difficulty?
when more miners join the network, the network raises the difficulty which makes it harder to guess the nonce that satisfies the constraint imposed by the difficulty setting
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It is important for miners to observe the rules because they must recoup their expenses in electricity. Therefore PoW is established when they receive BR and fees.
It would be extremely difficult to change a previous added block because the Hash would then change and the chain would the be broken on the next block as the Hash would now be different.
The network regulate mining difficulty by lowering the nonce making it harder to guess a lower number to complete the block.
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- Because you want to make sure the miners are following the rules, and the effort is what makes it proof of work
- Because it would change all subsequent blocks, throwing off the whole system
- By lowering the target, and making the nonce harder to find relative to the amount of people mining.
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- So that they have a reason to be fair and respect the rules of the game since they have something to lose.
- They will need to be able to control over 51% of all the harsh power which is practically impossible and costly.
- When they are more participants involved in mining the difficulty increases, and when they are less miners, the difficulty goes down.
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- To incentivize to play by the rules so they donāt loose money on electricity bills.
- Too expensive, time and costs involving.
- More miners increase the difficulty of catching nonce with lower target.
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To keep miner honest so that they can recoup the money spent and make a profit.
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It would be difficult because they would have to re-mine every block that comes after that block themselves which is a very slow process. during this time new blocks are being created so it would be impossible to catch up.
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The more miners mining, the harder the difficulty.
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- Why is it important to make sure that miners spend money (on electricity) while mining?
The cost to mine is incentive to keep mining to both cover costs and make a profit. It also keeps away dishonest miners because corrupted blocks will be rejected and the dishonest miner would still incur a cost.
- Why would it be very difficult for someone to go back change a previously added block?
If someone changes a previous block, the hash will be changed and links between all subsequent blocks will be broken. It would be virtually impossible to replace all subsequent blocks because much time and energy would need to be spent to find new hashes.
- How does the network regulate mining difficulty?
The network sets a lower target nonce when difficulty is high - higher difficulty happens when there are more miners in the network.
- Why is it important to make sure that miners spend money (on electricity) while mining?
The blockchain is miners dependant to keep adding new blocks to the end of the chain. Not any block, but a verified one whose transactions make sense. There are many reasons why is needed for miners to have dificult challenge that is translated into electricity consumption. The first one, by design, the inflationary bitcoin system requires that new blocks must be added to the system roughly every 10 minutes. Therefore the hashrate difficulty is adjusted depending on the number of miners outthere and the aggregate computation capabilities in order to meet the 10 minutes timespan. The miners are incentivized to participate in the competition and spending a lot of money in electricity, because winers get the inflationay rewards of the new coins plus the transaction fees. However, the winerās new block must be accepted by the rest of the miners (confirmations) before to add to the blockchain and harvest the rewards. If a dishonest miner tries to add a block with ilegal transactions, the rest of the comunity will reject and look forward the next winer. Thus the dishonest will end up losing money in the form of the electricity already spent. This is another powerful reason why miners must spend electricity, because it works as a severe penalty against bad actors.
- Why would it be very difficult for someone to go back change a previously added block?
All blocks are chained with a hash number made from three inputs: the previous block, the block itself with the transactions, and a NONCE number. The slightest change in any of these inputs invalidate the link. In order to make the new block valid the miner must find the new hash and that requires a lot computation. Letās suppose the miner was succesful in changing a previous block however all the rest of the blocks coming after are inmediately invalidated and the miner should do the same for the rest. A miner will be left behind as new blocks the honest miners keep adding. So, in theory, while possible to change a block in the practice itās impossible. A miner will require thosands of years and spend way too much energy to corrupt the system, unlessā¦ a miner has more than 50% of the entire system mining capacity. This is call the 51% attack. This is a theme for other lecture.
- How does the network regulate mining difficulty?
Itās been said that by design new blocks must be added roughle every ten minutes. So if the system detects an upgrade in computational capacity, lowers the hash target. This means that for a new block to be accepted, the hash should be lower to the specified target. Therefore the miners randomly changes the NONCE and by trial and error search for the one that produces a valid hash. In case thereās a drop in the aggregate mining capacity, the target is raised in order to make it easier to find a valid hash.
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Actually, acording to Ivan, the main reason why itās important for miners to spend in electricity, is to keep away dishonest miners. Corrupted blocks will be reject by the miners network and the bad actor would have incurr in a sensless cost.
Your answer in Q2 is alright, but it needs to be said that in order to replace the susequent blocks, the dishonest miner would have to spend too much time and energy in order to find the propper hashes for the new blocks. That makes the task virtually impossible.
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By spending money on the electricity, they are incentivized to follow the rules to get the reward. They want to make that money back that theyve spent on electricity and make a profit
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Because all blocks are connected and the puzzles that miners have to solve are correlated to the previous blocks, if you were to change anything in a previous block, you would have to re-solve every puzzle for every block moving forward. On top of whihc, as you are going back solving old blocks, miners are currently still building new blocks on the blockchain, making it basically impossible to catch up
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The more miners means more hash rate means the more difficult it is to guess the nonce. They do this by lowering the target
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