- If the miners spend money they will follow the rules as they are invested in the mining process.
- If someone changes something in a previously block it would break the link to the next block and the following blocks.
- The more miners that are in the network it would be harder to guess the nonce as the number targeted would be lowered. You have to guess a number lower than the target and the lower the target the harder it is to guess it.
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It is important to make sure that miners spend money on electricity while mining to ensure proof of work (or POW), which helps to maintain the integrity of the blockchain and the value of the cryptocurrency. It also ensure the difficulty of solving the puzzle for the nonce can increase with the number of miners (more miners means more electricity required to solve the puzzle).
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It would be very difficult for someone to go back and change a previously added block because each block’s hash is connected to the previous one. This creates a chain reaction. So in order to modify a single block in the blockchain, this would require enough computing power to mine all the blocks that follow the block someone would attempt to modify.
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The network regulates mining difficulty by decreasing the target number for the nonce. This smaller window in which the nonce exists means the range of wrong guesses increases proportionally.
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Why is it important to make sure that miners spend money (on electricity) while mining?
so they are investing in it which would give them more reason to secure the blockchain.
- Why would it be very difficult for someone to go back change a previously added block?
They would have to have 51% of the hashpower which would be very expensive. One change in the blockchain would mean the whole chain would have to be redone. - How does the network regulate mining difficulty?
The network regulates the mining difficulty if there are too many miners then the difficulty goes up and if miners leave it goes down.
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Why is it important to make sure that miners spend money (on electricity) while mining?
To provide an incentive for miners to recoup their losses -
Why would it be very difficult for someone to go back change a previously added block?
Because it will change the hash of that block and any connected block and so break the connection and require all those blocks to be re-mined. -
How does the network regulate mining difficulty?
By making the target lower as teh number of miners increase.
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- If they spend the money in advance on electricity, they are motivated to follow the rules to cover the costs and earn some extra money.
- It would change the hashes in all following blocks and new blocks would be added to the blockchain in the meantime. It would take impossible computing power to do this sooner than in thousands of years.
- The more miners there are, the lower the target number. This increases the mining difficulty.
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By spending money they are investing their time and money into the network. Working at a loss which should incentivise miners to play by the rules to win block rewards/tx fees and become profitable.
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By changing a previous tx it would involve them reguessing the nonce, using extremely high hash power (time/money) to amend txs and re-mine all previous and future blocks. It would take 1000s of years to do such a thing.
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By setting a “target” level. That is a number the miners have to beat in order to have their block amended to the network. The higher the number of miners, the lower the threshold it is for miners to get the correct number.
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1)Why is it important to make sure that miners spend money (on electricity) while mining?
2)Why would it be very difficult for someone to go back change a previously added block?
3)How does the network regulate mining difficulty?
1)Its an incentive that makes it worthwhile for them.
2)Because then they would have to change all the following blocks. The incentive is no longer there because they would no longer earn money.
3)Mining difficulty is regulated by the total network hash rate, which means that if a lot of miners leave the network, then the difficulty reduces drastically.
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- because they have operation costs and will certainly loose money, if they play foul (and then have no chance to mine the next block)
- because the network always trusts the longest chain of blocks - one would have to mine new blocks on his own faster, than all other network participients … which is impossible (in theory it would be possible, if you hade 51% hashpower for yourself)
- the goal is, that a new block is mined around every 10 minutes. so the mining difficulty will be increased, if there is a lot of miners/computercalculation-power “fighting” for the next block. and accaordingly lowered, in the opposite case.
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- To ensure honesty, everyone wants to make money, no one likes to lose it. Trying to cheat will result in a block being rejected therefore the miner would lose money on the electricity already spent on solving the puzzle.
- All block hashes following, plus the previous block of the one manipulated, would have to be resolved. Any additional blocks created would also have to be resolved, creating a scenario of forever trying to catch up.
- Difficulty target is raised or lowered to increase or decrease the ease of solving to maintain an average of 1 block per 10 min cycle.
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1.The miners are incentives play by the rules since they spend electricity.
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If anything changed in the previous block - that would break all forward connections between blocks.
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By setting the target high/low.
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Why is it important to make sure that miners spend money (on electricity) while mining?
The use of electricity is the investment that every miner has to make. When they have been playing by the rules they will get the block reward and the fee for the new block they had been producing -
Why would it be very difficult for someone to go back to change a previously added block?
The cost of electricity will be much higher than just producing legally new block -
How does the network regulate mining difficulty?
By changing the Target when more miners are mining .The lower the Target -More difficult to solve the puzzle
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1. Why is it important to make sure that miners spend money (on electricity) while mining?
It incentivizes them to be honest. If they mine a block full of errors, not only do they not get paid, they actually lose the money they’ve spent on electricity. Having already invested money in electricity up front, they are incentivized to be honest and efficient.
2. Why would it be very difficult for someone to go back change a previously added block?
If someone altered the transactions on a block they would also in effect be changing the hash. Since the hash is determined in part by the previous block’s hash, that means all the blocks in the chain that occurred after this block would have to be changed as well or their links would become broken. And even if that were possible, the person would then have to change all the new blocks that were created after their alteration began. No one has that kind of computing power. Maybe in the future with Quantum computers but not now.
3. How does the network regulate mining difficulty?
The more miners there are mining a network the lower the target and thus the more difficult it will be. This is because miners have to essentially hash in a circle. They hash the Transaction List, the previous Hash and they guess at the Nonce. Once they’ve hashed this combo, they have to compare their Hash with the Target and see if their Hash is lower. The lower the target, the fewer the options thus the more difficult it is. If their Hash isn’t lower than the target they have to start the process all over.
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- It’s important for miners to spend money while mining to show proof of work (POW). This adds inherent value to the block formation and hence to the Bitcoin.
- It would be difficult for someone to change a previously added block because this would change the block hash, the link of this block to the previous block (since the link is based on the hash of this block and the previous block’s hash) and finally, the proposed change we are discussing would also change all the following blocks’ hashes Because they are all based on the hash’s of the blocks before them). these changes to one block will require the miner to recalculate all the Nonces on all blocks going forward from this point on.
- The network regulates the mining difficulty by lowering the nonce threshold as more miners compete this adds more possibilities and hence, the time it takes to guess the correct Nonce.
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1- Why is it important to make sure that miners spend money (on electricity) while mining?
They use electricity to power systems fast enough to solve the cryptographic puzzle.
They are paying in advance for power and h/w that incentivizes miners to play by
the rules or they lose money.
2- Why would it be very difficult for someone to go back change a previously added block?
Because you would have to re-create all the previous blocks faster than all other miners
combined and it would take 1000’s of years or have 51% of all mining capacity.
Either way it would take billions of $ to make it happen.
3- How does the network regulate mining difficulty?
By dynamically adjusting difficulty every 2016 blocks based on the time it took to discover the 2016 previous blocks to keep the block discovery rate at 10 minutes.
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1- It makes the Bitcoin ecosystem more secure by making it almost impossible to alter the
previous transactions on the blockchain
2- to change a transaction on a block, you would have to go to that block, make the necessary change and then re-mine that block and every other block in front of that block with a hashrate higher than 51% to allow your blockchain to become the longest chain which will be ultimately be seen as the true chain by the network.
3- a target threshold is set for the hash of a block looking to be mined
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- It ensures that the miners will be honest & secure the bitcoin network with no issues.
- Each block includes data from the previous block so it would break the chain.
- When there are more miners the difficulty to guess the nonce is increased by lowering the target.
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- Why is it important to make sure that miners spend money (on electricity) while mining?
Mining with electricity gives bitcoin invested PoW market value, insentivises miners to follow network rules and adds further security to network.
- Why would it be very difficult for someone to go back change a previously added block?
Changing a single bit in any hash will changed all hashes in blocks that follow. A miner/mining pool would need to rehash again all blocks ahead of the one they are trying change, faster than all the other miners are confirming and have the longest block. Theoretically possible yet practically impossible.
- How does the network regulate mining difficulty?
The network regulates mining difficulty by adjusting the nonce threshold. Lowering the nonce increases difficulty, raising it lowers the difficulty. This is done to optimize new blocks found at a rate of one per 10 min approximately.
The difficulty is adjusted by the network every 2016 blocks.
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1- When miners spend electricity they have a vested interest, investment the Bi-product of which is incentive. To follow the rules (protocol) and to provide work in maintaining the Blockchain.
2- as covered in previous modules, the blockchain and it’s transactions are immutable. If one transaction is changed in a block, all blocks from that point forward in the chain must be re-mined. Up to and including all new blocks added.
“Possible in theory, impossible in practice”
That being said, Chinese build the Great Wall, Egyptians build the Pyramids…
3- As number of miners increases, difficulty increases.
The nonce target is lowered, leaving fewer possibilities for the algorithmic puzzle to be solved.
Question:
What happens in 120 years when the 21 millionth BTC is mined?
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The reason to make miners spend money (electricity) it to punish them by making them lose money if they are dishonest.
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It would be very difficult because not only will they have to replace the ones after that block as the hash will change and become invalid for those blocks, but they would have to mine fast enough to catch up to the others mining as well. Which would need 2x the mining speed of others.
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The network regulates by lowering the protocol and raising the difficulty to make sure blocks are mined with aprox 10 mins apart.
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- Why is it important to make sure that miners spend money (on electricity) while mining?
- Why would it be very difficult for someone to go back change a previously added block?
- How does the network regulate mining difficulty?
- This way, cheating will cause the cheater to lose money, as they spent it on electricity and didn’t gain anything.
- They would need to re-mine the block, as it got changed by changing its previous block. By that time, someone would mine the next (valid) block. The valid chain would be then longer at least by 1 block. The longes blockchain is considered valid by the network.
- By setting a target hash (from 0 to infinity). The closer the target is to 0, the harder to guess it correctly. The block’s hash is based on: block’s data, the block’s nonce, and the previous block’s hash. Mining requires guessing the nonce, that would cause the block’s hash to meet the network target hash constraint.
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