4 ms·

Gets a few facts wrong— E.g. the maximum block size is 1MB not 10MB, and there is no facility to increase it without replacing all the software—it's as fundame

by nullc 14y ago

Gets a few facts wrong— E.g. the maximum block size is 1MB not 10MB, and there is no facility to increase it without replacing all the software—it's as fundamentally hard to change as the supply of coins because it's also a scarcity which is essential to the security of the system. (without it, the system would rapidly become centralized as miners produced enormous blocks taking every single with-fee transaction; and then no one but miners could afford the computational, storage, and network costs of validating the gigantic blocks; nor would there be reason to pay substantive transaction fees to fund security). Overall it's pretty good.

oleganza 14y ago
Thanks, updated with the correction. However, the block size limit has nothing to do with scarcity and competition. If there were no limit, nothing would change today as number of transactions created is not even approaching 1 Mb per 10 minutes. And if somebody wants to create a lot of spam, they would have to pay for that in form of fees to compensate for the wasted bandwidth and blockchain storage. If I understand correctly, the block size is limited to make block distribution smoother across the peers + limit the disk space consumption until there are lightweight clients. Please correct me if I'm wrong.
- vessenes 14y ago
  That's correct. 1MB has a lot more to do with the mechanics of moving validated data across a peer to peer network than anything else.
hnolable 14y ago
Also wrong, 'Can the government shut it down?' Should be: Q. Who can shut it down? A. Anyone who is willing to pay 51% of the monthly operating cost of all miners. Plus an initial investment to manufacture the hardware. Neither of these numbers are out of the range of Governments or Banks. And they probably won't be for a long time. This is the death of Bitcoin scenario that worries me most. And it seems no one is really worrying about it or taking it seriously. edit: Here are the numbers someone calculated at the height of the first mining bubble [1]. We're currently at less than double the hashing power of then [2]. So a current rough estimate would be to double all those numbers. [1] http://bitcoin.stackexchange.com/a/1094 http://bitcoin.stackexchange.com/a/1094 [2] http://bitcoin.sipa.be/speed-lin-ever.png http://bitcoin.sipa.be/speed-lin-ever.png
- sp332 14y ago
  Controlling only 51% of the current operating power of the miners would take over eventually but it would take a very long time. Since each client trusts the longest chain, you would have to recompute a new chain that's longer than the entire chain so far. If you only pay for an extra 1% over the "legitimate" chain, it would take several years to make a longer chain.
  - hnolable 14y ago
    You're thinking of the wrong scenario. If you have 51% of the power you start mining a new block off the latest legit block but you include 0 or no "real" transactions in it. After you find one, you only compute new blocks off of _your_ "bad" last block. Since you have 51% you will control the entire blockchain from this point on. And you can basically shut down all transactions. Note that we aren't trying to reverse any transactions or steal people's bitcoin. We are just trying to stop all transactions. This is what bitcoin is all about, so do this and you've destroyed bitcoin.
    - blake8086 14y ago
      51% doesn't mean you always "win" a block, just that you win 51% of the time.
      - hnolable 14y ago
        Ok I'll bite and explain it. You're right, sometimes someone else will find a block before you and will add it onto the longest existing chain. IF you always appended your bad blocks to the longest chain then the blockchain would look something like bad->bad->good->bad->bad->good->bad->bad. BUT you WONT be adding your blocks to the longest chain. You will always add your blocks to YOUR OWN last bad block. So you will always be working on a blockchain that looks like ... ->bad->bad->bad->bad. And since you have 51% of the power your blockchain will eventually always be longer than the other chain(s) miners are working on. For a while the two chains (legitimate and your bad one) will go back and forth between which is longer. But at some point yours will get long enough and outpace the legitimate one. If you don't understand this you don't understand how bitcoin works. I don't say this to be a dick, but I say it because this is a real concern that a lot of people don't realize or think about.

by nullc 14y ago

oleganza 14y ago

Thanks, updated with the correction. However, the block size limit has nothing to do with scarcity and competition. If there were no limit, nothing would change today as number of transactions created is not even approaching 1 Mb per 10 minutes. And if somebody wants to create a lot of spam, they would have to pay for that in form of fees to compensate for the wasted bandwidth and blockchain storage. If I understand correctly, the block size is limited to make block distribution smoother across the peers + limit the disk space consumption until there are lightweight clients. Please correct me if I'm wrong.

vessenes 14y ago
That's correct. 1MB has a lot more to do with the mechanics of moving validated data across a peer to peer network than anything else.

hnolable 14y ago

Also wrong, 'Can the government shut it down?' Should be: Q. Who can shut it down? A. Anyone who is willing to pay 51% of the monthly operating cost of all miners. Plus an initial investment to manufacture the hardware. Neither of these numbers are out of the range of Governments or Banks. And they probably won't be for a long time. This is the death of Bitcoin scenario that worries me most. And it seems no one is really worrying about it or taking it seriously. edit: Here are the numbers someone calculated at the height of the first mining bubble [1]. We're currently at less than double the hashing power of then [2]. So a current rough estimate would be to double all those numbers. [1] http://bitcoin.stackexchange.com/a/1094 http://bitcoin.stackexchange.com/a/1094 [2] http://bitcoin.sipa.be/speed-lin-ever.png http://bitcoin.sipa.be/speed-lin-ever.png

sp332 14y ago
Controlling only 51% of the current operating power of the miners would take over eventually but it would take a very long time. Since each client trusts the longest chain, you would have to recompute a new chain that's longer than the entire chain so far. If you only pay for an extra 1% over the "legitimate" chain, it would take several years to make a longer chain.
- hnolable 14y ago
  You're thinking of the wrong scenario. If you have 51% of the power you start mining a new block off the latest legit block but you include 0 or no "real" transactions in it. After you find one, you only compute new blocks off of _your_ "bad" last block. Since you have 51% you will control the entire blockchain from this point on. And you can basically shut down all transactions. Note that we aren't trying to reverse any transactions or steal people's bitcoin. We are just trying to stop all transactions. This is what bitcoin is all about, so do this and you've destroyed bitcoin.
  - blake8086 14y ago
    51% doesn't mean you always "win" a block, just that you win 51% of the time.
    - hnolable 14y ago
      Ok I'll bite and explain it. You're right, sometimes someone else will find a block before you and will add it onto the longest existing chain. IF you always appended your bad blocks to the longest chain then the blockchain would look something like bad->bad->good->bad->bad->good->bad->bad. BUT you WONT be adding your blocks to the longest chain. You will always add your blocks to YOUR OWN last bad block. So you will always be working on a blockchain that looks like ... ->bad->bad->bad->bad. And since you have 51% of the power your blockchain will eventually always be longer than the other chain(s) miners are working on. For a while the two chains (legitimate and your bad one) will go back and forth between which is longer. But at some point yours will get long enough and outpace the legitimate one. If you don't understand this you don't understand how bitcoin works. I don't say this to be a dick, but I say it because this is a real concern that a lot of people don't realize or think about.