3 ms·

No, it doesn't. Bitcoin's difficulty automatically scales based on how fast the previous blocks were "solved". With that, if miners start dropping off, then the

by rabuse 4y ago

No, it doesn't. Bitcoin's difficulty automatically scales based on how fast the previous blocks were "solved". With that, if miners start dropping off, then the protocol will adjust for the falloff in "hashrate".

adgjlsfhk1 4y ago
the problem is that Bitcoin mining has to be sufficiently popular for the network to be secure. if the amount of miming ever drops too low, it becomes attackable.
- Animats 4y ago
  Which has happened to many of the lesser altcoins. Look for a boom in that, with all those underutilized GPU miners.
- sph 4y ago
  How would the amount of mining drop too low? There are only two cases: - Miners fall off the face of the Earth. Bitcoin is still valuable so others rush to their place because there is money to be made. - Bitcoin stops having any meaningful value due to other factors, so there is no reason to mine. There is no option that Bitcoin is valuable and everybody stops mining thus opening the network to attack.
  - cowtools 4y ago
    >- Miners fall off the face of the Earth. Bitcoin is still valuable so others rush to their place because there is money to be made. Your logic does not follow. What I am saying is this: You cannot continue to halve the mining rewards while maintaining network security. At some point you reach a point where the cost/benefit of attacking bitcoin (whether that be a deliberate 51% attack or a selfish mining scheme) outweighs the cost/benefit of mining faithfully. There may be some irrational agents who continue to mine at a loss, but they will be outnumbered by rational agents with more capital.
    - sph 4y ago
      Your argument assumes that the Bitcoin price stops rising after halving, which does not make any economical sense. And even when all Bitcoin has been mined, transaction fees will prop miners up (though it hasn't happened yet so it's valid to be doubtful this'll happen in practice) And also depends what you mean by securing. All clients, miners and not, are capable of checking transaction and discarding "insecure" and invalid chains. I don't need a miner to tell me if your transaction is valid or not.
      - cowtools 4y ago
        >transaction fees will prop miners up (though it hasn't happened yet so it's valid to be doubtful this'll happen in practice) No, they won't. This is a common talking point, but it is rarely accompanied by facts. Consider that fees currently amount to about about a percent of the total miner payout. There is some research that indicates that bitcoin is vulnerable to a class of double-spending attacks known as selfish mining: https://eprint.iacr.org/2020/094.pdf https://eprint.iacr.org/2020/094.pdf http://fc14.ifca.ai/papers/fc14_submission_82.pdf http://fc14.ifca.ai/papers/fc14_submission_82.pdf >And also depends what you mean by securing. All clients, miners and not, are capable of checking transaction and discarding "insecure" and invalid chains. I don't need a miner to tell me if your transaction is valid or not. No they aren't. You misunderstand the fundamental design of bitcoin. The problem is not that the non-mining nodes cannot verify signatures or something, the problem is that these non-mining nodes will not be able prove to each other that the signatures to not refer to already spent funds. The non-mining nodes cannot conclusively prevent reorgs that can be used for double-spend attacks. >All clients, miners and not, are capable of checking transaction and discarding "insecure" and invalid chains. They do this by selecting the chain with the highest amount of PoW associated with it. If the network hashrate is low relative to an attacker, then any attacker will be able to easily overpower the network and decide which chains are invalid. If you are new, I recommend this video on bitcoin's design: https://www.youtube.com/watch?v=bBC-nXj3Ng4 https://www.youtube.com/watch?v=bBC-nXj3Ng4
        sph 4y ago
        I am not new to Bitcoin but I appreciate the link to the two papers, which I should probably dive into. All I've heard about the transaction fees problem is that "no one knows for sure, it's still too early to tell." From a cursory look, the papers suggest it's possible to update the protocol/consensus to detect and thwart that type of attacks, and while Bitcoin is slow moving, it's not static and there's still plenty of time to find a decent fix to that issue.
cowtools 4y ago
The literal hashrate is irrelevant. What matters is the comparative cost/reward of an attacker performing an attack on the network, which will continue to decrease for the reasons i've stated. Sure, the protocol will adjust for the falloff in hash-rate as miners ditch their hardware- a perfect opportunity for a malicious entity to buy up their hardware and use it to attack the network.
- TakeBlaster16 4y ago
  But what is the comparative reward you're talking about here? The world is filled with situations where something with lesser economic value secures something with higher value. That's a sign of efficiency. My house is worth $250K. But you couldn't capture that much value by breaking in, so I haven't spent $250K on a security system. If I did need another $250K to secure my first $250K investment, it wouldn't be a great investment. Suppose it only takes $3.5B to attack a $7.3T network. So what? Unless your plan is to burn billions of dollars for funsies, you'll need to capture at least $4B worth of value for that attack to be worth it. You think you can find someone to anonymously make a $4B crypto sale to you, who won't know where to hunt you down when you try to 51% away the transaction after the next block in 10 minutes?

by rabuse 4y ago

adgjlsfhk1 4y ago

the problem is that Bitcoin mining has to be sufficiently popular for the network to be secure. if the amount of miming ever drops too low, it becomes attackable.

Animats 4y ago
Which has happened to many of the lesser altcoins. Look for a boom in that, with all those underutilized GPU miners.
sph 4y ago
How would the amount of mining drop too low? There are only two cases: - Miners fall off the face of the Earth. Bitcoin is still valuable so others rush to their place because there is money to be made. - Bitcoin stops having any meaningful value due to other factors, so there is no reason to mine. There is no option that Bitcoin is valuable and everybody stops mining thus opening the network to attack.
- cowtools 4y ago
  >- Miners fall off the face of the Earth. Bitcoin is still valuable so others rush to their place because there is money to be made. Your logic does not follow. What I am saying is this: You cannot continue to halve the mining rewards while maintaining network security. At some point you reach a point where the cost/benefit of attacking bitcoin (whether that be a deliberate 51% attack or a selfish mining scheme) outweighs the cost/benefit of mining faithfully. There may be some irrational agents who continue to mine at a loss, but they will be outnumbered by rational agents with more capital.
  - sph 4y ago
    Your argument assumes that the Bitcoin price stops rising after halving, which does not make any economical sense. And even when all Bitcoin has been mined, transaction fees will prop miners up (though it hasn't happened yet so it's valid to be doubtful this'll happen in practice) And also depends what you mean by securing. All clients, miners and not, are capable of checking transaction and discarding "insecure" and invalid chains. I don't need a miner to tell me if your transaction is valid or not.
    - cowtools 4y ago
      >transaction fees will prop miners up (though it hasn't happened yet so it's valid to be doubtful this'll happen in practice) No, they won't. This is a common talking point, but it is rarely accompanied by facts. Consider that fees currently amount to about about a percent of the total miner payout. There is some research that indicates that bitcoin is vulnerable to a class of double-spending attacks known as selfish mining: https://eprint.iacr.org/2020/094.pdf https://eprint.iacr.org/2020/094.pdf http://fc14.ifca.ai/papers/fc14_submission_82.pdf http://fc14.ifca.ai/papers/fc14_submission_82.pdf >And also depends what you mean by securing. All clients, miners and not, are capable of checking transaction and discarding "insecure" and invalid chains. I don't need a miner to tell me if your transaction is valid or not. No they aren't. You misunderstand the fundamental design of bitcoin. The problem is not that the non-mining nodes cannot verify signatures or something, the problem is that these non-mining nodes will not be able prove to each other that the signatures to not refer to already spent funds. The non-mining nodes cannot conclusively prevent reorgs that can be used for double-spend attacks. >All clients, miners and not, are capable of checking transaction and discarding "insecure" and invalid chains. They do this by selecting the chain with the highest amount of PoW associated with it. If the network hashrate is low relative to an attacker, then any attacker will be able to easily overpower the network and decide which chains are invalid. If you are new, I recommend this video on bitcoin's design: https://www.youtube.com/watch?v=bBC-nXj3Ng4 https://www.youtube.com/watch?v=bBC-nXj3Ng4
      - sph 4y ago
        I am not new to Bitcoin but I appreciate the link to the two papers, which I should probably dive into. All I've heard about the transaction fees problem is that "no one knows for sure, it's still too early to tell." From a cursory look, the papers suggest it's possible to update the protocol/consensus to detect and thwart that type of attacks, and while Bitcoin is slow moving, it's not static and there's still plenty of time to find a decent fix to that issue.

cowtools 4y ago

The literal hashrate is irrelevant. What matters is the comparative cost/reward of an attacker performing an attack on the network, which will continue to decrease for the reasons i've stated. Sure, the protocol will adjust for the falloff in hash-rate as miners ditch their hardware- a perfect opportunity for a malicious entity to buy up their hardware and use it to attack the network.

TakeBlaster16 4y ago
But what is the comparative reward you're talking about here? The world is filled with situations where something with lesser economic value secures something with higher value. That's a sign of efficiency. My house is worth $250K. But you couldn't capture that much value by breaking in, so I haven't spent $250K on a security system. If I did need another $250K to secure my first $250K investment, it wouldn't be a great investment. Suppose it only takes $3.5B to attack a $7.3T network. So what? Unless your plan is to burn billions of dollars for funsies, you'll need to capture at least $4B worth of value for that attack to be worth it. You think you can find someone to anonymously make a $4B crypto sale to you, who won't know where to hunt you down when you try to 51% away the transaction after the next block in 10 minutes?