-
Why is it important to make sure that miners spend money (on electricity) while mining?
-> its the concept of proof of work which gives miners the incentive to get a block reward but only if thy don’t try to cheat the system. -
Why would it be very difficult for someone to go back change a previously added block?
-> because all blocks that were created after the previous block would be completely changed
and invalidated and would have to be re-mined. This would be theoretically possible but practically impossible because is would take to long and would be too expensive to do, to play this catch up game. -
How does the network regulate mining difficulty?
-> The more miners are online the lower is higher the mining difficulty, or the other way around
Thanks dude! Yeah I understand I think I just didnt explain it well enough. I do alot of these pretty late at night 
No problem, we are al human beings full of mistakes. And it’s not easy to express your toughts into words. 
-
Spending money for electricity will incentivize miners to play by the rules and make profit.
-
Each block is connected to the previous block, if you change something in a block, you have to change all the other blocks too.
-
It adjustes the mining difficulty by changing the target number.
[1.] It important to make sure that miners spend money (on electricity) while mining so as to prevent them from trying to enter fraudulent info into the blockchain. If the other nodes in the blockchain realize the block your trying to add is corrupted, it would be rejected and there goes the money the miner spent on solving the puzzle.
[2.] It would be very difficult for someone to go back change a previously added block because it would affect all the hash values of all the following blocks and to recalculate all of them would take very, very, very long.
[3.] The network regulate mining difficulty by increasing it when the amount of miners increases.
- Miners need to spend money to make money. The electricity is real world value that drives the price of bitcoin.
- All blocks are chained together with a hashes, nothing can be changed unless you have more than 51% of the total hash power.
- Mining difficulty increases as the number of miners increases.
- The fact to spend money in electricity for the miners proof that there is a cost in getting block rewards and it motivates them to do everything in the right way
- it would be difficult to change anything in the previous added block because the next added blocks should be changed too and its impossible to change everything quickly.
- after each block added in the blockchain, the nonce number of the next block should be lower in the target.
-
Why is it important to make sure that miners spend money (on electricity) while mining?
This ensures that the miners will play by the rules, by having to pay to mine. -
Why would it be very difficult for someone to go back change a previously added block?
Because if you change just one block, every block after that has to be changed as well, this would make it prohibitively expensive to do. -
How does the network regulate mining difficulty?
By lowering the target for the hash, difficulty of finding the nonce increases. By increasing the target for the hash, the difficulty decreases.
-
The POW mechanism in a blockchain mimics a fundamental truth that energy needs to be put in for energy to be taken out. Gold had / has to be mined from the earth, refined, minted, and distributed as money and that takes capital, or energy to accomplish. This unlike our FIAT money system that takes almost nothing to produce what most people today consider as money. Proof that work was done through the Hashing of a new block incentives the miners to protect the network and incentives the network to be used through sound fundamentals.
-
Trying to change a previous block in order to garner some reward would be, currently, improbable. This is because that every block that follows the altered block would have to be re-mined due to the variation in the Hashed outputs of those blocks with the altering of the previous block. The network would detect this alteration and reject it.
-
Mining difficulty increases based on the Hash power of the network. As the Hash power goes up the target value goes down. The smaller the target the harder it is for you to hit that target. This is a self correcting mechanism that adjusts over time.
-
Because if they do not follow the blockchain protocol it will cost them to mine rather then earn to mine. it is also the power of the network.
-
Because it will chnage all input and every block before and after menning it will make the blockchain invalid.
-
By youseing a “target”. which is a lower number of possible hash which makes the odds of you mining the nonce smaller. the more miners the lower target.
-
Its is important that miners spend money (through the cost of electricity) so there is an incentive to maintain a ‘truthful’ & ‘honest’ record of what occured on the blockchain. Essentially, miners pay up-front to get rewarded for being honest.
-
The difficulty & cost of altering a previous block is important as it helps maintain a secure network.
-
The network regulates difficulty within the code so that the target of the nonce is lower when the hash rate rate increases. This is important so that blocks are mined approximately every 10 minutes.
- Why is it important to make sure that miners spend money (on electricity) while mining?
So they have a incentive not to waste electricity as they are committed to following the rules so it is not wasted - Why would it be very difficult for someone to go back change a previously added block?
As this would change the hash and doing so change the blocks after causing them to be re mined - How does the network regulate mining difficulty?
It adjusts the difficulty when more miners come online increasing the difficulty, or drop the difficulty when they go offline
[/quote]
- Why is it important to make sure that miners spend money (on electricity) while mining?
It is important for miners to pay upfront with electricity so that they have something to lose if they attempt to act maliciously or dishonestly. If they verify a transaction that doesn’t follow the rules their block will be rejected and the electricity they have used mining will go to waste. This results in it only making sense to participate honestly and follow the rules of the network.
- Why would it be very difficult for someone to go back change a previously added block?
In order for someone to go back and change a previously added block they would require control over 51% of the hashing power for a period long enough to overtake the chain being worked on by everyone else. After changing the data they would find that the nonce in that block no longer places its hash within the difficulty target making the block invalid. This means they would need to calculate a new nonce. After finding a new nonce they would find that all subsequent blocks on their chain are also invalid - because the hash of the previous block enters each block before the nonce is found. This means they would have to single-handedly remine the entire chain from the changed block onwards before catching up with the rest of the network. This requires more processor time than even the largest nation states could produce and exponentially more depending on how far back the change is made. In this respect all transactions become increasingly change-resistant the older they are and the longer the blockchain becomes.
- How does the network regulate mining difficulty?
When many people are mining it is important to not allow the hash rate to exceed an average of ten minutes per block. The protocol implements this by adjusting the difficulty every 2016 blocks. The hash target will become lower so the probability of finding a nonce that will hash within this target is reduced, requiring more guesswork (hashing power) to mine the block. Likewise if the hash rate starts to take longer than ten minutes per block the target will become larger making it easier for miners to secure the network.
- Why is it important to make sure that miners spend money (on electricity) while mining?
So that they’ve invested in the mining and have incentives to follow rules and be honest. - Why would it be very difficult for someone to go back change a previously added block?
Previously, current and all following blocks would be changed and the link between them broken, and it would nearly be impossible to fix later on (unless using 51% rule). Also new blocks may’ve been created in the meantime which makes it even harder. - How does the network regulate mining difficulty?
If many people on the network the target will be set lower and therefore the nonce will be harder to guess, and opposite.
Regulates itself, approx. one block every 10 mins.
1. Why is it important to make sure that miners spend money (on electricity) while mining?
Because they are invested they are incentivised to follow the rules, because if they don’t they can loose (a lot) of money.
2. Why would it be very difficult for someone to go back change a previously added block?
Because all the blocks are cryptographically linked together one can not simply go back and change one block without having to re-mine all the subsequent blocks. This requires an insane amount of hashing power (=costs).
3. How does the network regulate mining difficulty?
By increasing or decreasing the target.
- Why is it important to make sure that miners spend money (on electricity) while mining?
It incentivizes miners to play by the rules. Spending money on electricity for GPU power in order to nonce which leads to POW and financial rewards. - Why would it be very difficult for someone to go back change a previously added block?
It would take too much GPU(electricity) power to go back and change the entire block, not financially rewarding. - How does the network regulate mining difficulty?
The more people mining (hash rate) the lower the TARGET that has to be nonced. Target miners trying to nonce is determined by “difficulty-how many people are mining” Target low when difficulty is high.
Because they first need to spend some value as a collateral to the network that they will play by the rules.
Because every little change to any previous block will completely change the hash of that block and every next one. For the network the longest chain is valid therefore it would take tremendous amount of computing power to alter all blocks.
More miners there are, the difficulty is being increased by lowering the target.
To make them follow the rules. If they don’t follow the rules all money spend is lost.
Changing a block will invalidate all following blocks of the chain. You would need to re-mine all of them.
Using a fixed hard coded time-rule. Block should be created every 10 minutes. Any diviation to that will cause an adjustmen of the difficulty. If new blocks are created too fast the difficulty will increase, meaning that more hash-power is needed to find new blocks. If new blocks are created too slow the difficulty will be reduced, meaning that less has-power is needed because it is easier to find new blocks.
The security of the network is based on the amount of miners and their hash-power. Therefore the side effect of reducing the difficulty also means that the network is weakened.
-
it is important to make sure they spend money to have something in stake. Miners are mining for incentive - to earn bitcoin. They will only earn bitcoin if they behave according to the rules of the network. They have to know that if they break the rules, they will not only earn bitcoin (to pay for electricity + profit) but they will also lose money for the power.
Thus it is called POW - miners invest work and electricity to secure thew network. -
because every block is linked and tied to their successor block, that means if someone would change something in the past block, it would impact all blocks after that one. If that attacker wanted to do that, he would have to re-mine all the following blocks… that is virtually impossible for bad actor, unless he controls at least 51% of hashrate and even then it would cost so much that it would not be worth to anyone.
-
network reviews the amount of active hashrate every period of time and also checks how long it takes to mine a block in average. According to that difficulty either rise or fall. When difficulty rise, the target hash becomes lower so it is more time consuming to “guess” the right nonce, if difficulty needs to be lowered, it goes the other way.
Homework on Mining and Proof of Work - Questions
- Why is it important to make sure that miners spend money (on electricity) while mining?
- significant upfront fixed costs to incentive miners to play by rules to attain a ROI.
- Why would it be very difficult for someone to go back change a previously added block?
Every block is hashed by the data inside the block combined with the hash of the previous block. If a previous block is changed; all hashes become invalid. Remining is requied.
- How does the network regulate mining difficulty?