imsaguy
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June 25, 2012, 05:41:37 PM |
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Just for laughs, I'll use my 2016 blocks per day example for some calculations. 2016 blocks per day is 14 times as fast as the network wants to go, so at the end of day one the diff would rise at the max rate of 4x. Now that 2016 blocks takes 4x as long to create, it will be 4 days before the next retarget interval. 4 days is still 3.5x as fast as the network wants to go, so at the end of 4 more days the diff will rise again, but this time by 3.5x. Now, the diff is 14 times higher than it was 5 days ago, and the block creation time is now back on track to where it should be. Therefore, in 5 days of mining, the network has adjusted the difficulty to neutralize this hashing monster, and keep the block flowing at a steady pace.
Between each difficulty increase, the network produces 2016 blocks. So if you've increased 3 times in 5 days, you've made 3x2016 blocks in 5 days. That's 6048 blocks or 302,400 bitcoins. Now you see why people are having wet dreams.
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sadpandatech
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June 25, 2012, 05:41:42 PM |
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Remember that even with 51%, no attacker can spend your or others' coins. They can only spend their own, prevent your transactions from occurring, and roll back your and others' transactions at will. That last part becomes more and more difficult with the passing of time, and depending on how much hash power the attacker has.
aye, if they had 51% they definitly would not have a shortage of BTC to play with. ;p And yea, the rolling back of a huge volume of transactions seems very concerning.
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If you're not excited by the idea of being an early adopter 'now', then you should come back in three or four years and either tell us "Told you it'd never work!" or join what should, by then, be a much more stable and easier-to-use system. - GA
It is being worked on by smart people. -DamienBlack
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Cablez
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I owe my soul to the Bitcoin code...
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June 25, 2012, 05:41:58 PM |
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This is where I fail in my understanding of the double spend. Suppose someone gets the hashpower (costly) and goes through with this 'attack', wouldn't it be self defeating? I mean everyone can follow the transaction trees so they would know when/if it happened and at that point wouldn't bitcoin become completely useless as everyone loses trust and pulls out? The attacker only really has one attempt to profit on this before the house of cards falls down correct?
Or is it a case of blind denial and people will try to fix the attackers changes and keep bitcoin limping along even though the trust is now shattered?
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Tired of substandard power distribution in your ASIC setup??? Chris' Custom Cablez will get you sorted out right! No job too hard so PM me for a quote Check my products or ask a question here: https://bitcointalk.org/index.php?topic=74397.0
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rjk
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1ngldh
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June 25, 2012, 05:43:11 PM |
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So if you've increased 3 times in 5 days, you've made 3x2016 blocks in 5 days. That's 6048 blocks or 302,400 bitcoins. Now you see why people are having wet dreams.
Have fun cashing out.
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mcorlett
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June 25, 2012, 05:43:31 PM |
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Aye, so pretty much like I'm imagining then. Sooo, how many merchants are able to deliver a product before the blocks resume and the chargeback happens. I mean if the 51% is sustained long enough to be noticed by devs would we not be able to fork from it?
You don't know until it's too late. The attacker starts mining on a chain of their own, without broadcasting the blocks to the outside world. They could be 100 blocks ahead of us right now, and you wouldn't know it. On their chain they're still in possession of their bitcoins, while they spend them all on our chain. When they're happy with the fruits of their spending frenzy, they unleash upon us their chain, which is immediately accepted because it is longer.
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sadpandatech
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June 25, 2012, 05:45:42 PM |
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Aye, so pretty much like I'm imagining then. Sooo, how many merchants are able to deliver a product before the blocks resume and the chargeback happens. I mean if the 51% is sustained long enough to be noticed by devs would we not be able to fork from it?
You don't know until it's too late. The attacker starts mining on a chain of their own, without broadcasting the blocks to the network. They could be 100 blocks ahead of us right now, and you wouldn't know it. On their chain they're still in possession of their bitcoins, while they spend them all on our chain. When they're happy with the fruits of their spending frenzy, they unleash upon us their chain, which is immediately accepted because it is longer. ahhhh, I see. edit; But, how would they spend coins on our chain before overwriting the chain? So the only other hurdle for them is building a chain to match the length of the current one before joining? Of course they can likely do this all at difficulty 1?
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If you're not excited by the idea of being an early adopter 'now', then you should come back in three or four years and either tell us "Told you it'd never work!" or join what should, by then, be a much more stable and easier-to-use system. - GA
It is being worked on by smart people. -DamienBlack
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imsaguy
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Don't send me a pm unless you gpg encrypt it.
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June 25, 2012, 05:47:27 PM |
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Aye, so pretty much like I'm imagining then. Sooo, how many merchants are able to deliver a product before the blocks resume and the chargeback happens. I mean if the 51% is sustained long enough to be noticed by devs would we not be able to fork from it?
You don't know until it's too late. The attacker starts mining on a chain of their own, without broadcasting the blocks to the outside world. They could be 100 blocks ahead of us right now, and you wouldn't know it. On their chain they're still in possession of their bitcoins, while they spend them all on our chain. When they're happy with the fruits of their spending frenzy, they unleash upon us their chain, which is immediately accepted because it is longer. Or something a bit more subtle.. like refusing to include transactions unless a higher transaction fee is paid. Sure other people could try to mine them, but eventually, they'll be orphaned.
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rjk
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1ngldh
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June 25, 2012, 05:47:41 PM |
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Aye, so pretty much like I'm imagining then. Sooo, how many merchants are able to deliver a product before the blocks resume and the chargeback happens. I mean if the 51% is sustained long enough to be noticed by devs would we not be able to fork from it?
You don't know until it's too late. The attacker starts mining on a chain of their own, without broadcasting the blocks to the network. They could be 100 blocks ahead of us right now, and you wouldn't know it. On their chain they're still in possession of their bitcoins, while they spend them all on our chain. When they're happy with the fruits of their spending frenzy, they unleash upon us their chain, which is immediately accepted because it is longer. ahhhh, I see. So the only other hurdle for them is building a chain to match the length of the current one before joining? Of course they can likely do this all at difficulty 1? The chain building must conform to the current network parameters, including difficulty. It must be built without leaking onto the internet at any point (slightly difficult), and if it doesn't match what the network expects when it is released, that would cause it to be rejected and all that hash power wasted.
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mcorlett
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June 25, 2012, 05:51:25 PM |
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Or something a bit more subtle.. like refusing to include transactions unless a higher transaction fee is paid. Sure other people could try to mine them, but eventually, they'll be orphaned.
Meh, they would make more from screwing over a single merchant with a double-spend than a lifetime of transaction fee extortion, and people would abandon Bitcoin in both cases.
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sadpandatech
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June 25, 2012, 05:54:49 PM |
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Aye, so pretty much like I'm imagining then. Sooo, how many merchants are able to deliver a product before the blocks resume and the chargeback happens. I mean if the 51% is sustained long enough to be noticed by devs would we not be able to fork from it?
You don't know until it's too late. The attacker starts mining on a chain of their own, without broadcasting the blocks to the network. They could be 100 blocks ahead of us right now, and you wouldn't know it. On their chain they're still in possession of their bitcoins, while they spend them all on our chain. When they're happy with the fruits of their spending frenzy, they unleash upon us their chain, which is immediately accepted because it is longer. ahhhh, I see. So the only other hurdle for them is building a chain to match the length of the current one before joining? Of course they can likely do this all at difficulty 1? The chain building must conform to the current network parameters, including difficulty. It must be built without leaking onto the internet at any point (slightly difficult), and if it doesn't match what the network expects when it is released, that would cause it to be rejected and all that hash power wasted. ahh, thought they could atleast cheat the difficulty. Soo, if they had the hash power to build a matching chain would they not make more money by just mining thereal chain? Or would the benefit have to be not neccesairly motivated by money then? haha, I love the fee extortion idea. ;p Why not, it seems someone actually doing this would have to be a bit bonkers to begin with. ;p
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If you're not excited by the idea of being an early adopter 'now', then you should come back in three or four years and either tell us "Told you it'd never work!" or join what should, by then, be a much more stable and easier-to-use system. - GA
It is being worked on by smart people. -DamienBlack
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imsaguy
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Don't send me a pm unless you gpg encrypt it.
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June 25, 2012, 05:58:33 PM |
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Or something a bit more subtle.. like refusing to include transactions unless a higher transaction fee is paid. Sure other people could try to mine them, but eventually, they'll be orphaned.
Meh, they would make more from screwing over a single merchant with a double-spend than a lifetime of transaction fee extortion, and people would abandon Bitcoin in both cases. Eventually this will happen anyway once the rewarding drops further. You'll see further consolidation as mining margins shrink which will slowly give the mining companies much more say with what goes on.
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rjk
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1ngldh
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June 25, 2012, 06:03:55 PM |
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ahh, thought they could atleast cheat the difficulty. Soo, if they had the hash power to build a matching chain would they not make more money by just mining thereal chain? Or would the benefit have to be not neccesairly motivated by money then?
haha, I love the fee extortion idea. ;p Why not, it seems someone actually doing this would have to be a bit bonkers to begin with. ;p
Well at that point, they would have all the coins mined from their fake chain which has now been accepted as real, as well as whatever they were able to bilk out of the merchants that they fleeced with a double-spend. In other words, a shit ton of coins.
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mcorlett
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June 25, 2012, 06:05:13 PM |
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ahh, thought they could atleast cheat the difficulty. Soo, if they had the hash power to build a matching chain would they not make more money by just mining thereal chain? Or would the benefit have to be not neccesairly motivated by money then?
Actually, they sort of can. There is the "Zeitgeist attack". (I prefer "Time travel attack", but that's beside the point.) It works on the premise of artificially modifying the block timestamps so as to "confuse" the algorithm that retargets the difficulty. ArtForz describes it here. tl;dr: an attacker can perform the attack with marginally less hashing power
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sadpandatech
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June 25, 2012, 07:17:21 PM |
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Once all this new 'allegedly' available asic tech comes online the network will be a shit ton stronger against this sort of attack.
so BFL = savior of the blockchain and BFL = destroyer of miner's dreams
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If you're not excited by the idea of being an early adopter 'now', then you should come back in three or four years and either tell us "Told you it'd never work!" or join what should, by then, be a much more stable and easier-to-use system. - GA
It is being worked on by smart people. -DamienBlack
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rjk
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1ngldh
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June 25, 2012, 07:19:30 PM |
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Once all this new 'allegedly' available asic tech comes online the network will be a shit ton stronger against this sort of attack.
so BFL = savior of the blockchain and BFL = destroyer of miner's dreams
If it materializes, then yes pretty much. Along with Vladimir's proposed ASIC farm, the difficulty in the future is going to be damn high.
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Paladin69 (OP)
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June 26, 2012, 12:07:33 AM |
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I'm trying to visualize what this all means. Soon the 7200 bitcoins per day max will be halved to 3600.
So now we have 3600 bitcoins spread out among...what would people guess...200TH/s once ASIC hits? 2,000TH/s?
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sadpandatech
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June 26, 2012, 12:47:33 AM |
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I'm trying to visualize what this all means. Soon the 7200 bitcoins per day max will be halved to 3600.
So now we have 3600 bitcoins spread out among...what would people guess...200TH/s once ASIC hits? 2,000TH/s?
aye, it's really hard to speculate now and comes down to just how much miners are willing to spend to buy asics. The preorders currently put the new hash rate at maybe 45TH by reward halving(much citation needed still). And will be largely influenced by how well the release goes and whether that encourages more miners to buy equipment or not.
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If you're not excited by the idea of being an early adopter 'now', then you should come back in three or four years and either tell us "Told you it'd never work!" or join what should, by then, be a much more stable and easier-to-use system. - GA
It is being worked on by smart people. -DamienBlack
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MrTeal
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June 26, 2012, 01:11:19 AM |
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I'm trying to visualize what this all means. Soon the 7200 bitcoins per day max will be halved to 3600.
So now we have 3600 bitcoins spread out among...what would people guess...200TH/s once ASIC hits? 2,000TH/s?
aye, it's really hard to speculate now and comes down to just how much miners are willing to spend to buy asics. The preorders currently put the new hash rate at maybe 45TH by reward halving(much citation needed still). And will be largely influenced by how well the release goes and whether that encourages more miners to buy equipment or not. BFL won't get to 2000TH/s any time soon. If you think about it, using the current SC ASICs that would be 2000 MiniRigs or 50,000 singles. Given the little we know about BFL's production and assuming that the new singles/minirigs take as long to produce as the old ones, how long do you think it will take to get 50,000 singles out the door? Of course, the $70M that would bring in at current prices finance quite the expansion.
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crazy_rabbit
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RUM AND CARROTS: A PIRATE LIFE FOR ME
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June 26, 2012, 03:46:43 PM |
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I'm trying to visualize what this all means. Soon the 7200 bitcoins per day max will be halved to 3600.
So now we have 3600 bitcoins spread out among...what would people guess...200TH/s once ASIC hits? 2,000TH/s?
aye, it's really hard to speculate now and comes down to just how much miners are willing to spend to buy asics. The preorders currently put the new hash rate at maybe 45TH by reward halving(much citation needed still). And will be largely influenced by how well the release goes and whether that encourages more miners to buy equipment or not. BFL won't get to 2000TH/s any time soon. If you think about it, using the current SC ASICs that would be 2000 MiniRigs or 50,000 singles. Given the little we know about BFL's production and assuming that the new singles/minirigs take as long to produce as the old ones, how long do you think it will take to get 50,000 singles out the door? Of course, the $70M that would bring in at current prices finance quite the expansion. We know via Bit-Pay that they got at least a quarter million dollars yesterday alone. http://www.marketwatch.com/story/bitpay-shatters-record-for-bitcoin-payment-processing-2012-06-26That buys 8.3 minirigs or 8.3 Terahashes.
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more or less retired.
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MrTeal
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June 26, 2012, 07:01:09 PM |
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I'm trying to visualize what this all means. Soon the 7200 bitcoins per day max will be halved to 3600.
So now we have 3600 bitcoins spread out among...what would people guess...200TH/s once ASIC hits? 2,000TH/s?
aye, it's really hard to speculate now and comes down to just how much miners are willing to spend to buy asics. The preorders currently put the new hash rate at maybe 45TH by reward halving(much citation needed still). And will be largely influenced by how well the release goes and whether that encourages more miners to buy equipment or not. BFL won't get to 2000TH/s any time soon. If you think about it, using the current SC ASICs that would be 2000 MiniRigs or 50,000 singles. Given the little we know about BFL's production and assuming that the new singles/minirigs take as long to produce as the old ones, how long do you think it will take to get 50,000 singles out the door? Of course, the $70M that would bring in at current prices finance quite the expansion. We know via Bit-Pay that they got at least a quarter million dollars yesterday alone. http://www.marketwatch.com/story/bitpay-shatters-record-for-bitcoin-payment-processing-2012-06-26That buys 8.3 minirigs or 8.3 Terahashes. Do you think they'll be able to ship out 8.3TH/s worth of gear in one day?
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