10 ms·

Here’s who probably did that $150 million Bitcoin transaction

167 points by rkudeshi 13y ago

cheez 13y ago
This is why I can't take Bitcoin seriously. The privacy implications are insane.
- VaucGiaps 13y ago
  What do you mean exactly? If you want, you can say which addresses are yours. If you don't: privacy!
  - nitrogen 13y ago
    Without running through a mixer, aren't one's transactions are vulnerable to being followed through the network of addresses back to the point of origin, and forward to the destination?
    - sidko 13y ago
      Depends on where you first entered the 'system' that makes you reveal your identity. For example, if you buy on localbitcoins in a face to face exchange without the need of identification, it wouldn't be feasible to track the Bitcoins to your real identity. Sovereign money to Bitcoin conversion is the spot where identities are revealed. Otherwise, it remains pseudonymous.
- zgoldberg 13y ago
  Why is privacy a necessary property of a "serious" currency? Just because that's the precedent doesn't mean it's the 'right way'.
  - pearjuice 13y ago
    Because Bitcoin its only applicable use case is to buy drugs with. What's the point if it's without privacy?
- josephagoss 13y ago
  Please stop with the privacy scaremongering. A lot of work is currently going into trustless mixing/anonymising services that will largely stop this type of tracking. (coinjoin/zerocoin) A lot of us are investing with the expectation true anonymous transactions eventually happen, because when they do Bitcoin will become even more valuable.
  - cheez 13y ago
    It's not scaremongering. Can you trust the mixing services?
    - tedunangst 13y ago
      The more mixing is done, the higher the daily bitcoin transaction volume is, and the more trustworthy bitcoin becomes!
  - gnaritas 13y ago
    > A lot of work is currently going into trustless mixing/anonymising Call it what it is, money laundering.
    - VMG 13y ago
      It isn't.
      - hbags 13y ago
        A mixer's sole purpose in life is collect a fee for concealing sources of money. It's textbook money laundering.
        VMG 13y ago
        Except with Bitcoin, there are valid reasons to conceal the source and destination of money from the public besides criminal activity. The money being "laundered" isn't necessarily "dirty" to begin with. The same logic applies to encryption. People have a right to privacy.
- Element_ 13y ago
  Traditional currency isn't really anonymous. Sure it is theoretically possible to do an anonymous 150 million dollar cash transaction in USD but in practical terms it's basically impossible without a great deal of money laundering. I believe by law in North America banks have to report any cash transactions >= 10k per 24 hour period to the government. Additionally every bill has a traceable serial number on it.
  - ams6110 13y ago
    There is no history of every transaction in which a given serial number appears however. So in that sense it's easier to hide origins... even if the Fed knows which bank got that note originally, it's very likely that there's no trace of it after that unless it was involved in a specific tracked transaction (uncover police drug buy, etc.)
  - movingahead 13y ago
    In India, if you deposit more than Rupees 50,000 ( roughly USD 850) to another person's account in cash, you need to provide your PAN card number - which is a unique number issued by the Income Tax Authority. I am sure a huge number of transactions are done illegally beyond this system but the threshold for anonymous legal transactions is pretty low.
- josu 13y ago
  Bitcoin is public by default
- mdisraeli 13y ago
  This is why I take bitcoin seriously, the privacy implications are BRILLIANT :P In all seriousness, this is going to come across as a conspiracy theory, but why else would major government organisations be thinking that bitcoin is actually a good thing? Surveillance by design neatly negates all the current NSA privacy issues! It is also a figurative goldmine for economics researchers, who get to study every transaction in an economy for once, with full information on how the funds are following. There's quite a few of us who have been concerned for a while about the issue of who controls the bitchain, as the only real thing stopping a single entity from doing this is cost. Yet the advantages are so very high. There's also the very real possibility that you don't actually need 51% of miners to do this for specific purposes, either. Just look at some of the TOR monitoring research. EDIT: I should also add that we need to be talking about these issues, rather than dismissing them. If the cryptocurrency movement is to survive, then these are the challenges ahead. And one has to ask, if this is not the sole means of accepted currency, are these issues actually a concern? What would count as appropriate mitigation? Can multiple forms of cryptocurrency co-exist and serve different purposes?
  - snitko 13y ago
    > but why else would major government organisations be thinking that bitcoin is actually a good thing? Because they realized it would be impossible to fight it and, more importantly, because they probably invested in it themselves. Bitcoin being non-anonymous is a problem that can be solved and is being currently solved.
  - jasimp 13y ago
    > It is also a figurative goldmine for economics researchers, who get to study every transaction in an economy for once, with full information on how the funds are following. If you're interested in that than you should look at the economy for Eve Online. It's definitely the closest thing ever created to a real economy which astounding amounts of information available to study. I'll provide some links that talk about Eve's market from economic standpoints, but these really only scratch the surface of what type of analysis is possible. [NOTE: I am not an author of any of these posts, and I claim no ownership over them] http://justinandrewjohnson.com/gaming/eve-online-best-game-economists http://justinandrewjohnson.com/gaming/eve-online-best-game-e... http://justinandrewjohnson.com/gaming/The-EVE-Online-Monopoly-Part-1 http://justinandrewjohnson.com/gaming/The-EVE-Online-Monopol...
- logicallee 13y ago
  And this is why I can take Bitcoin seriously. Can you imagine if it were really completely anonymous, and someone could be spending a hundred million dollars on, say, a nuclear bomb, without any record, association, or so much as someonel leaving the house and delivering a suitcase full of cash? Imagine if Russia become a failed state or bribeable - you really want to be able to pay off a hundred million dollars to some general there with no more record - to us, to the rest of Russia, or to anyone else, including at any future point that the general would spend any of that money, than if you typed md5 'haha now i'm nuclear' at a bash shell on some disconnected PC? I think this aspect of btc is great. To see what you're talking about, go ahead and type echo -n Haha I\'m nuclear! | md5sum at the prompt and see if you think that a financial transaction of any amount should be as totally untraceable as the cryptographic operation you just performed locally. Really, come on. Also we already had a case of ransomware. How about ransomware that attacks a nuclear facility, flight control tower, hydroelectric plant or whatever else, and threatens to immediately cause damage if a ransom isn't paid. You really want that to be totally 100% off of any ledger anywhere - and not even include a delivery of a briefcase full of cash? Nor any way to follow any of that money at any point whatsoever? I think btc pseudonymity is a fine compromise.
  - maxerickson 13y ago
    Your examples are more implausible than they are logical.
    - logicallee 13y ago
      Here are some simple examples from this site, https://news.ycombinator.com/item?id=4404362 https://news.ycombinator.com/item?id=4404362 - "Hackers Steal, Encrypt Health Records and Hold Data for Ransom". and recently https://news.ycombinator.com/item?id=6567735 https://news.ycombinator.com/item?id=6567735 - "You’re infected—if you want to see your data again, pay us $300 in Bitcoins" A top comment on that article said: It actually made my skin crawl reading about it. Never had that reaction to such a story before. Interesting... You might think this might have been a speculative work of fiction. It wasn't - this is a story that happened. As for your run of the mill kidnappings for ransom, blackmail, extortion and other things normal people turn to the FBI with, (that you would too, if you got certain very specific threatening letters for example), I think if you come back after 5 minutes of googling the subject you would not consider the general situation to be speculative. We are talking about sources of blackmail, kidnapping and ransom becoming literally completely untraceable, without even a network effect of where the money is going afterward (what pseudonymous addresses). As for the infrastructural, nuclear and so forth examples, you will observe that placing or turning moles and spies already occurs historically, which shows that the process is possible. You are talking about lowering the barrier to entry and risk profile. Literally anyone who is in a position to do something, and understands that they could instantly anonymously receive a the digital equivalent of a briefcase full of cash, without it ever showing up anywhere, without needing to hide it as they spend it (except regarding the effect it would have on their visible lifestyle -- hell, they could anonymously transfer it to some fake lottery that pretends they just won it...nothing would ever connect the two, the lottery could be a complete front and seem 100% legitimate. Or even actually be 99% legitimate, with a single person adding another payout while collecting funds for it from the person being paid and making sure the lotteries ledger's add up... you get the idea.) It would be a disaster to have absolutely zero leads whatsoever in all such cases. Money has a profound effect on the world and a modicum of possible pseudonymous oversight over its movements is quite a bit more than minimally responsible. Ask yourself, for hte data ransoming story I linked: would you prefer for the btc address to be totally and completely a black box, or the present state of affairs? Really, the current implementation is an absolute minimum for 'keeping people honest'. It has a very high level of barrier to de-anonymizing users (as far as I understand it), yet given sufficient resources certain leads can at least be put together.
- cenhyperion 13y ago
  Yes, I still don't understand why people assumed it was a safe way to pay for incredibly illegal things. Unless you take extreme precautions tracking down the individual behind a wallet would be trivial for a government.
antonius 13y ago
Once wallets become available that can mask this type of public exposure, bitcoin popularity and usage will grow even more.
chubot 13y ago
I haven't been following closely, but could it have been the FBI transferring Silk Road funds to their own address? Given the timing that seems to make sense.
- sidko 13y ago
  They've always tagged the seized coins either with 'Silkroad seized coins' or 'DPR seized coins' in the past. e.g. https://blockchain.info/address/1F1tAaz5x1HUXrCNLbtMDqcw6o5GNn4xqX https://blockchain.info/address/1F1tAaz5x1HUXrCNLbtMDqcw6o5G...
  - nawitus 13y ago
    Who did the tagging?
    - nwh 13y ago
      Users of blockchain.info. It's a little obvious, the amounts they transferred are "FBI" when typed on a phone keyboard.
hbz 13y ago
This type of "sophisticated analysis" will be useless whenever zerocoin is proven as a viable addition to the protocol. True anonymity is scary from a regulatory standpoint but extremely desirable to many others.
- dllthomas 13y ago
  I would be unsurprised if use of zerocoin winds up being treated as money laundering.
rheide 13y ago
I wonder if it ever becomes viable to try to brute-force the private key of such a valuable address, rather than devoting the brute force power to mining. Edit: got curious and found an answer: http://bitcoin.stackexchange.com/questions/2847/how-long-would-it-take-a-large-computer-to-crack-a-private-key http://bitcoin.stackexchange.com/questions/2847/how-long-wou... If I understand correctly, it's still not viable even if you tried your brute-forced keys on all addresses in the network.
- cpach 13y ago
  So much easier to crack the box holding the key.
  - ams6110 13y ago
    Which is why the key hopefully isn't stored on any system that is remotely accessible.
    - nwh 13y ago
      Given it got broken up into 4000BTC chunks after the box TX, we can assume they are on paper wallets, probably distributed up using secret sharing. That's standard in the Bitcoin world.
    - qixxiq 13y ago
      I'm not sure people are aware/scared enough of possible physical access. People have been kidnapped / banks robbed / etc for far less than $150MM.
    - ye 13y ago
      That's the cool thing about Bitcoin. You can create a wallet on a completely offline computer or even a virtual computer, save the address and the private key, and send the money to it. You only need the internet connection to do something with the coins.
  - pfortuny 13y ago
    Probably a well-crafted phone call would be as useful... "I am the administrator of MtGox, I need you to send us a copy of your private key..."
bradleysmith 13y ago
Here's the cited paper from UCSD on bitcoin address analysis: http://cseweb.ucsd.edu/~smeiklejohn/files/imc13.pdf http://cseweb.ucsd.edu/~smeiklejohn/files/imc13.pdf
afs35mm 13y ago
Very curious how Meiklejohn came to associate the 12sENw address with Bitstamp...
joshguthrie 13y ago
Today's goals: * Spend 100 million for supercomputers to compute this address's wallet in one day. * Acquire said wallet. * Reimburse my 100 million debt. * Enjoy my 50 millions. Anybody got supercomputers?
- jamestnz 13y ago
  The numbers for this, sadly (or gladly, for holders of bitcoin), don't work out. Even if you had the most powerful supercomputer in the world and could try trillions upon trillions of keys per second, you'd need, on average, more than the current age of the universe to brute-force the key. From: http://bitcoin.stackexchange.com/questions/22/is-it-possible-to-brute-force-bitcoin-address-creation-in-order-to-steal-money/3205#3205 http://bitcoin.stackexchange.com/questions/22/is-it-possible... In order to spend money sent to a Bitcoin address, you just need to find a ECDSA public key that hashes to the same 160 bit value. That will take, on average, 2 ^ 160 key generations. Supposing you could generate a billion (2 ^ 30) per second, you need 2 ^ 130 seconds. Doing this in parallel using a billion machines requires only 2 ^ 100 seconds. Getting a billion of your richest friends to join you gets it down to only 2 ^ 70 seconds. There are about 2 ^ 25 seconds per year, so you need 2 ^ 45 years. The age of the Universe is about 2 ^ 34 years so far—better get cracking!
jgalt212 13y ago
This reminds me of when actual users were identified from the "anonymous" AOL search logs. http://www.nytimes.com/2006/08/09/technology/09aol.html?pagewanted=all&_r=0 http://www.nytimes.com/2006/08/09/technology/09aol.html?page... Anonymity is not privacy.
ToastyMallows 13y ago
Anyone know where I can get one of those bitcoin keychains in the picture? :) Edit: Found it, http://bkeychain.com/buy.html http://bkeychain.com/buy.html ($12??)
- bhartzer 13y ago
  How many bit coins to get one of those?

167 points by rkudeshi 13y ago

cheez 13y ago

This is why I can't take Bitcoin seriously. The privacy implications are insane.

VaucGiaps 13y ago
What do you mean exactly? If you want, you can say which addresses are yours. If you don't: privacy!
- nitrogen 13y ago
  Without running through a mixer, aren't one's transactions are vulnerable to being followed through the network of addresses back to the point of origin, and forward to the destination?
  - sidko 13y ago
    Depends on where you first entered the 'system' that makes you reveal your identity. For example, if you buy on localbitcoins in a face to face exchange without the need of identification, it wouldn't be feasible to track the Bitcoins to your real identity. Sovereign money to Bitcoin conversion is the spot where identities are revealed. Otherwise, it remains pseudonymous.
zgoldberg 13y ago
Why is privacy a necessary property of a "serious" currency? Just because that's the precedent doesn't mean it's the 'right way'.
- pearjuice 13y ago
  Because Bitcoin its only applicable use case is to buy drugs with. What's the point if it's without privacy?
josephagoss 13y ago
Please stop with the privacy scaremongering. A lot of work is currently going into trustless mixing/anonymising services that will largely stop this type of tracking. (coinjoin/zerocoin) A lot of us are investing with the expectation true anonymous transactions eventually happen, because when they do Bitcoin will become even more valuable.
- cheez 13y ago
  It's not scaremongering. Can you trust the mixing services?
  - tedunangst 13y ago
    The more mixing is done, the higher the daily bitcoin transaction volume is, and the more trustworthy bitcoin becomes!
- gnaritas 13y ago
  > A lot of work is currently going into trustless mixing/anonymising Call it what it is, money laundering.
  - VMG 13y ago
    It isn't.
    - hbags 13y ago
      A mixer's sole purpose in life is collect a fee for concealing sources of money. It's textbook money laundering.
      - VMG 13y ago
        Except with Bitcoin, there are valid reasons to conceal the source and destination of money from the public besides criminal activity. The money being "laundered" isn't necessarily "dirty" to begin with. The same logic applies to encryption. People have a right to privacy.
Element_ 13y ago
Traditional currency isn't really anonymous. Sure it is theoretically possible to do an anonymous 150 million dollar cash transaction in USD but in practical terms it's basically impossible without a great deal of money laundering. I believe by law in North America banks have to report any cash transactions >= 10k per 24 hour period to the government. Additionally every bill has a traceable serial number on it.
- ams6110 13y ago
  There is no history of every transaction in which a given serial number appears however. So in that sense it's easier to hide origins... even if the Fed knows which bank got that note originally, it's very likely that there's no trace of it after that unless it was involved in a specific tracked transaction (uncover police drug buy, etc.)
- movingahead 13y ago
  In India, if you deposit more than Rupees 50,000 ( roughly USD 850) to another person's account in cash, you need to provide your PAN card number - which is a unique number issued by the Income Tax Authority. I am sure a huge number of transactions are done illegally beyond this system but the threshold for anonymous legal transactions is pretty low.
josu 13y ago
Bitcoin is public by default
mdisraeli 13y ago
This is why I take bitcoin seriously, the privacy implications are BRILLIANT :P In all seriousness, this is going to come across as a conspiracy theory, but why else would major government organisations be thinking that bitcoin is actually a good thing? Surveillance by design neatly negates all the current NSA privacy issues! It is also a figurative goldmine for economics researchers, who get to study every transaction in an economy for once, with full information on how the funds are following. There's quite a few of us who have been concerned for a while about the issue of who controls the bitchain, as the only real thing stopping a single entity from doing this is cost. Yet the advantages are so very high. There's also the very real possibility that you don't actually need 51% of miners to do this for specific purposes, either. Just look at some of the TOR monitoring research. EDIT: I should also add that we need to be talking about these issues, rather than dismissing them. If the cryptocurrency movement is to survive, then these are the challenges ahead. And one has to ask, if this is not the sole means of accepted currency, are these issues actually a concern? What would count as appropriate mitigation? Can multiple forms of cryptocurrency co-exist and serve different purposes?
- snitko 13y ago
  > but why else would major government organisations be thinking that bitcoin is actually a good thing? Because they realized it would be impossible to fight it and, more importantly, because they probably invested in it themselves. Bitcoin being non-anonymous is a problem that can be solved and is being currently solved.
- jasimp 13y ago
  > It is also a figurative goldmine for economics researchers, who get to study every transaction in an economy for once, with full information on how the funds are following. If you're interested in that than you should look at the economy for Eve Online. It's definitely the closest thing ever created to a real economy which astounding amounts of information available to study. I'll provide some links that talk about Eve's market from economic standpoints, but these really only scratch the surface of what type of analysis is possible. [NOTE: I am not an author of any of these posts, and I claim no ownership over them] http://justinandrewjohnson.com/gaming/eve-online-best-game-economists http://justinandrewjohnson.com/gaming/eve-online-best-game-e... http://justinandrewjohnson.com/gaming/The-EVE-Online-Monopoly-Part-1 http://justinandrewjohnson.com/gaming/The-EVE-Online-Monopol...
logicallee 13y ago
And this is why I can take Bitcoin seriously. Can you imagine if it were really completely anonymous, and someone could be spending a hundred million dollars on, say, a nuclear bomb, without any record, association, or so much as someonel leaving the house and delivering a suitcase full of cash? Imagine if Russia become a failed state or bribeable - you really want to be able to pay off a hundred million dollars to some general there with no more record - to us, to the rest of Russia, or to anyone else, including at any future point that the general would spend any of that money, than if you typed md5 'haha now i'm nuclear' at a bash shell on some disconnected PC? I think this aspect of btc is great. To see what you're talking about, go ahead and type echo -n Haha I\'m nuclear! | md5sum at the prompt and see if you think that a financial transaction of any amount should be as totally untraceable as the cryptographic operation you just performed locally. Really, come on. Also we already had a case of ransomware. How about ransomware that attacks a nuclear facility, flight control tower, hydroelectric plant or whatever else, and threatens to immediately cause damage if a ransom isn't paid. You really want that to be totally 100% off of any ledger anywhere - and not even include a delivery of a briefcase full of cash? Nor any way to follow any of that money at any point whatsoever? I think btc pseudonymity is a fine compromise.
- maxerickson 13y ago
  Your examples are more implausible than they are logical.
  - logicallee 13y ago
    Here are some simple examples from this site, https://news.ycombinator.com/item?id=4404362 https://news.ycombinator.com/item?id=4404362 - "Hackers Steal, Encrypt Health Records and Hold Data for Ransom". and recently https://news.ycombinator.com/item?id=6567735 https://news.ycombinator.com/item?id=6567735 - "You’re infected—if you want to see your data again, pay us $300 in Bitcoins" A top comment on that article said: It actually made my skin crawl reading about it. Never had that reaction to such a story before. Interesting... You might think this might have been a speculative work of fiction. It wasn't - this is a story that happened. As for your run of the mill kidnappings for ransom, blackmail, extortion and other things normal people turn to the FBI with, (that you would too, if you got certain very specific threatening letters for example), I think if you come back after 5 minutes of googling the subject you would not consider the general situation to be speculative. We are talking about sources of blackmail, kidnapping and ransom becoming literally completely untraceable, without even a network effect of where the money is going afterward (what pseudonymous addresses). As for the infrastructural, nuclear and so forth examples, you will observe that placing or turning moles and spies already occurs historically, which shows that the process is possible. You are talking about lowering the barrier to entry and risk profile. Literally anyone who is in a position to do something, and understands that they could instantly anonymously receive a the digital equivalent of a briefcase full of cash, without it ever showing up anywhere, without needing to hide it as they spend it (except regarding the effect it would have on their visible lifestyle -- hell, they could anonymously transfer it to some fake lottery that pretends they just won it...nothing would ever connect the two, the lottery could be a complete front and seem 100% legitimate. Or even actually be 99% legitimate, with a single person adding another payout while collecting funds for it from the person being paid and making sure the lotteries ledger's add up... you get the idea.) It would be a disaster to have absolutely zero leads whatsoever in all such cases. Money has a profound effect on the world and a modicum of possible pseudonymous oversight over its movements is quite a bit more than minimally responsible. Ask yourself, for hte data ransoming story I linked: would you prefer for the btc address to be totally and completely a black box, or the present state of affairs? Really, the current implementation is an absolute minimum for 'keeping people honest'. It has a very high level of barrier to de-anonymizing users (as far as I understand it), yet given sufficient resources certain leads can at least be put together.
cenhyperion 13y ago
Yes, I still don't understand why people assumed it was a safe way to pay for incredibly illegal things. Unless you take extreme precautions tracking down the individual behind a wallet would be trivial for a government.

antonius 13y ago

Once wallets become available that can mask this type of public exposure, bitcoin popularity and usage will grow even more.

chubot 13y ago

I haven't been following closely, but could it have been the FBI transferring Silk Road funds to their own address? Given the timing that seems to make sense.

sidko 13y ago
They've always tagged the seized coins either with 'Silkroad seized coins' or 'DPR seized coins' in the past. e.g. https://blockchain.info/address/1F1tAaz5x1HUXrCNLbtMDqcw6o5GNn4xqX https://blockchain.info/address/1F1tAaz5x1HUXrCNLbtMDqcw6o5G...
- nawitus 13y ago
  Who did the tagging?
  - nwh 13y ago
    Users of blockchain.info. It's a little obvious, the amounts they transferred are "FBI" when typed on a phone keyboard.

hbz 13y ago

This type of "sophisticated analysis" will be useless whenever zerocoin is proven as a viable addition to the protocol. True anonymity is scary from a regulatory standpoint but extremely desirable to many others.

dllthomas 13y ago
I would be unsurprised if use of zerocoin winds up being treated as money laundering.

rheide 13y ago

I wonder if it ever becomes viable to try to brute-force the private key of such a valuable address, rather than devoting the brute force power to mining. Edit: got curious and found an answer: http://bitcoin.stackexchange.com/questions/2847/how-long-would-it-take-a-large-computer-to-crack-a-private-key http://bitcoin.stackexchange.com/questions/2847/how-long-wou... If I understand correctly, it's still not viable even if you tried your brute-forced keys on all addresses in the network.

cpach 13y ago
So much easier to crack the box holding the key.
- ams6110 13y ago
  Which is why the key hopefully isn't stored on any system that is remotely accessible.
  - nwh 13y ago
    Given it got broken up into 4000BTC chunks after the box TX, we can assume they are on paper wallets, probably distributed up using secret sharing. That's standard in the Bitcoin world.
  - qixxiq 13y ago
    I'm not sure people are aware/scared enough of possible physical access. People have been kidnapped / banks robbed / etc for far less than $150MM.
  - ye 13y ago
    That's the cool thing about Bitcoin. You can create a wallet on a completely offline computer or even a virtual computer, save the address and the private key, and send the money to it. You only need the internet connection to do something with the coins.
- pfortuny 13y ago
  Probably a well-crafted phone call would be as useful... "I am the administrator of MtGox, I need you to send us a copy of your private key..."

bradleysmith 13y ago

Here's the cited paper from UCSD on bitcoin address analysis: http://cseweb.ucsd.edu/~smeiklejohn/files/imc13.pdf http://cseweb.ucsd.edu/~smeiklejohn/files/imc13.pdf

afs35mm 13y ago

Very curious how Meiklejohn came to associate the 12sENw address with Bitstamp...

joshguthrie 13y ago

Today's goals: * Spend 100 million for supercomputers to compute this address's wallet in one day. * Acquire said wallet. * Reimburse my 100 million debt. * Enjoy my 50 millions. Anybody got supercomputers?

jamestnz 13y ago
The numbers for this, sadly (or gladly, for holders of bitcoin), don't work out. Even if you had the most powerful supercomputer in the world and could try trillions upon trillions of keys per second, you'd need, on average, more than the current age of the universe to brute-force the key. From: http://bitcoin.stackexchange.com/questions/22/is-it-possible-to-brute-force-bitcoin-address-creation-in-order-to-steal-money/3205#3205 http://bitcoin.stackexchange.com/questions/22/is-it-possible... In order to spend money sent to a Bitcoin address, you just need to find a ECDSA public key that hashes to the same 160 bit value. That will take, on average, 2 ^ 160 key generations. Supposing you could generate a billion (2 ^ 30) per second, you need 2 ^ 130 seconds. Doing this in parallel using a billion machines requires only 2 ^ 100 seconds. Getting a billion of your richest friends to join you gets it down to only 2 ^ 70 seconds. There are about 2 ^ 25 seconds per year, so you need 2 ^ 45 years. The age of the Universe is about 2 ^ 34 years so far—better get cracking!

jgalt212 13y ago

This reminds me of when actual users were identified from the "anonymous" AOL search logs. http://www.nytimes.com/2006/08/09/technology/09aol.html?pagewanted=all&_r=0 http://www.nytimes.com/2006/08/09/technology/09aol.html?page... Anonymity is not privacy.

ToastyMallows 13y ago

Anyone know where I can get one of those bitcoin keychains in the picture? :) Edit: Found it, http://bkeychain.com/buy.html http://bkeychain.com/buy.html ($12??)

bhartzer 13y ago
How many bit coins to get one of those?