This is considered one of the most unbreakable aspects of bitcoin. It would take all the hashing power in the world something like 10^50 years to brute force the private key (a.k.a. ain't gonna happen). One cool thing, if the address has never been spent out of it (only received coins), it is theoretically still safe from quantum computers.
A private key is not strictly necessary to receive coins, only to spend them. So while there is still probably a private key with that address (since he intended to actually be able to use those bitcoins), the public key is not revealed unless coins are spent from that address.
Yes, but this information is not published to the blockchain until you spend it.
The address is literally RIPEMD-160(SHA-256(public key)), plus a 4 byte checksum. To receive coins to that address, the sender publishes the amount they are sending and that address, they never see the public key.
When the owner of the address wants to send bitcoins from it, only then do they publish the public key, along with a transaction signed by their private key.
Ok, so I'm not a cryptography specialist, but I don't see how "address = RIPEMD-160(SHA-256(public key))" makes it impossible to derive the public key from the address if you have a quantum computer. Or is SHA-256 not vulnerable to quantum computing the way public/private keypairs are?
Yes that is correct. SHA256 is not known to be vulnerable to quantum computers[^], ECDSA (Bitcoin's public/private key algorithm) is.
[^] There is a known quantum attack against SHA256 that reduces the brute force search space from 2^256 to 2^128, but that wouldn't really break the Bitcoin protocol. The ECDSA quantum vulnerability, however, would make ECDSA essentially useless.
If you didn't shred the hard drive and haven't defragged it or anything, there's a good chance that the private keys are able to be recovered. There are scripts that will scan a drive for fragments that look like bitcoin-qt wallet files and dump the keys.
Interesting. I'm not sure which disk its on and it might well be corrupt but I had various components that I was going to make into a secondary desktop or donation machine so I suppose I should check while I test, it might pay for itself!
Put this on a bootable usb with ubuntu or something and run it against the drive in question. Let it run overnight, and in the morning, you may find yourself with a windfall.
After it runs, it will create a wallet.dat file that you will load with bitcoin-qt. If it works and you have the private keys, I would recommend exporting them into a better format, like an electrum or armory wallet.
It's not a display bug, it's a feature. It also has nothing to do with block chain accounting structures (which are never negative). It's the internal accounting system used by bitcoind/Bitcoin-Qt, exposed by a command line and JSON-RPC interface.
I'd transfer them over to another exchange and sell them, if I were you. The USD price on Mt. Gox can be considered fake because nobody can get their money out.
I have not tried in a bit...last time was 2 days. I have heard they had a backlog due to the withdrawl shutdown but of course that is speculation unless I try to transfer today and see how long it takes.
Well, you don't necessarily need to cash out to USD to withdraw from MtGox. Instead, you can transfer to an offline wallet with a few physical and/or cloud+encrypted backups.
My point is that the USD price on Mt. Gox isn't accurate because it isn't liquid. If money comes in, but never comes out, how can you know that money is worth x amount? If I give someone x money and they give me something in return that they say is worth the same amount of money that I gave them, but I can't actually get that amount for it, is it really worth that much?
Why do you think 13 with 100+ is wrong? They weren't worth much a few months ago, and this is a website for hackers. I wouldn't be surprised if 10 of those 13 have thousands of coins.
At one point I owned about 150 bitcoins, but I sold the majority off at the $30-something peak a few years back. I also paid for my bitcoin miner back when bitcoins were $11, and my cost was 58 bitcoins. The miner that I finally received, has made me 5 bitcoins.
I also bought at around $30. Back when the only way I could realistically get BTC was on IRC on #btc-otc using PayPal. I still have the original Excel spreadsheet I used to track the purchases and marking the ones where I got ripped off. Then it all went to shit in a few hours. Forgot about the coins until now.
It's equally probable that people are going to laugh their heads off in a few years that people were selling their coins at $300. I mean it was ridiculous to us that the $30 coins were selling at $250 in April.
That is not that much if you are dedicated to the idea of Bitcoin and make a point of investing a lot into them. I would not be surprised if a lot of Bitcoin die hards are also into StartUp culture and programming/building stuff.
I am actually surprised there are so few people who posted on the poll with 100+ Bitcoin.
I sometimes invest on Just-Dice and plenty of people have thousands of Bitcoin to throw around, a lot of these people are developers with a passion.
Didn't notice it as a phenomenon early enough to start mining with desktop and laptop CPUs and GPUs. Can't afford mining ASICs. Would not buy as, not only can I not afford it, I also don't speculate on foreign currency (though I realize that virtual currencies are a special case). So until Bitcoin gains ubiquity I ain’t likely to come into ownership of any. So 0 now and into the foreseeable future.
It's not a foreign currency. Think of it like gold. I rather think of myself as a human than as a <insert nationality from country I happened to be born in>. Gold is mine, and so is Bitcoin.
I threw away 30 coins during the first year of mining when you could get a coin a day on a half decent box... It's always made me annoyed at myself because I could buy a lot of pizza with those coins.
I sold 5 coins at the first peak of $31/BTC. Thought I was pretty damn sly for getting out ahead of the following crash ($8/BTC). Joke's on me! I've now lost out on $1230 and counting.
I was going to buy $300 worth when they were 30 cents each. I didn't, though, as it involved travel to a nearby town and I was working on a book and thought I should be practical and spend the weekend on that. Ah well, one less house.
Dude, you made the right choice. Just because things have been heading up for many Bitcoin users doesn't mean it's not speculation. Bitcoin will always have large value fluctuations since it is, unlike "real world" currencies, decoupled from the rest of the economy.
And if I was you, I'd do myself the favor of not torturing myself about what could have been.
Yes, there's definitely an element of speculation about it, but also of platform-building. I was depressed about it for awhile, but take it with a grain of salt now for the most part. It would nice to be financially independent, as some other friends of mine who were early adapters are, but hindsight is 20/20.
I own half of a Bitcoin. I purchased about two weeks ago. In the intervening time, the value of Bitcoin has gone up 40%. I can't complain, and I'll probably buy more in the near future. It is somewhat disappointing that they can't be used for anything, though. Without practical applications, Bitcoin is subject to massive volatility and doesn't have any sort of foundation to prevent against collapse of the market.
Incidentally, I also developed a Bitcoin Twitter ticker. If anyone would like to keep up with hourly prices via Twitter, I suggest that you check it out.
I'd say it's horrible for savings. Savings is something you actually want to "save", meaning its likelihood of retaining value is as close to 100% as possible. With low risk comes low return, which is okay for savings. Bitcoin is an investment at best, a speculation at worst. It definitely isn't a guaranteed store of value. It's easy to confuse the fact that it's going up with the idea of storing value. Not very long ago your "savings" would have been about 1/2 its peak value in April, and in a year it might be worth 10X or 1/10th.
At this point it is way too volatile for use as as long-term wealth storage. The current state of Bitcoing only makes it suitable for high-risk, high-reward investing, which is not conducive to saving.
No. It's only useful as savings if it can be reasonably expected to hold long-term value. But with a valuation based almost entirely on speculation there isn't really a rational reason to assume that (unlike, say, gold or silver which still have commercial use providing a price floor).
The last time someone did this, they mistakenly used "0-5 BTC" as the lowest cutoff. You've made the same mistake. There should be "0-0.25", "0.25-0.5", "0.5-0.75", "0.75-1", "1-2", "2-3", "3-4", and "4-5". Extra poll options are better because now we've lost valuable information at the low end. In 20 minutes, 65 people say they own 0-5 BTC. That's anywhere from $0 to $1385. That's a massive range. We now have no idea how many "casual" bitcoiners there are, because casuals will only have like $200 max.
EDIT: Here's what your poll looks like as of t=35min:
▆▁▁▁▁▁▁▁▁▁▁▂
Leftmost bar is 0-5BTC. Rightmost bar is 100+BTC. Oh look, now we know basically nothing about the two most interesting ranges.
It should be relativly simple to generate such a list. Unfourtuantly, the best I could find (in 5 minutes of googleing) is [1], which shows the ballance of a single account as a function of time.
Zero.. I recently owned 10 but sold them all when the price jumped to $200. I guess I was too quick on the trigger, but what can you do. Will be buying again in about a month when this hype cycle dies off.
Are you trying to day trade? Are you a long term bull? You gotta come up with an investing plan :)
One potential solution to your problem is to do something like: sell Y% of my coins everytime the price increases by X%. An example would be sell 20% after each 50% rise (semi bullish plan. I also made those numbers up, don't consider them as specific advice).
Glad to be helpful! Small clarification, just in case: sell Y% of the remaining coins. That way you will always have some, even if the price goes ballistic.
Yeah, but she said "no" when they were priced at $20-30.
I fully understand the risks involved. Heck, my Economics degree makes me 1% more qualified than most people here to talk about how bubbles work.
If I'd bought BTC, I'd have been more worried about technical problems. I don't claim to understand the system in depth, but I know that crypto-fails happen all the time.
If an exploit is ever discovered, I wonder what we'd do with all that surplus bitcoin mining hardware?
All 'yall need to be ashamed of yourselves if you don't own even a US penny's worth of Bitcoin. I'm not even kidding. If you've never witnessed a bitcoin transaction or held a bitcoin on an electronic device this far into the game, just hang your heads in shame.
Spend some time on /r/bitcoin. There's some good discussion, but also some talk on there that would cause you to run away for fear of association. Sometimes I'll go there and want to go somewhere with more intellectualism and open-mindedness, like say a Tea Party forum.
165 comments
[ 5.2 ms ] story [ 230 ms ] threadYou'll know if that happens, though, since the technique will obviously be used on the largest wallets first.
Side note: interestingly, right now, the largest wallet appears to be Dread Pirate Roberts' seized bitcoins held by the FBI.
The address is literally RIPEMD-160(SHA-256(public key)), plus a 4 byte checksum. To receive coins to that address, the sender publishes the amount they are sending and that address, they never see the public key.
When the owner of the address wants to send bitcoins from it, only then do they publish the public key, along with a transaction signed by their private key.
[^] There is a known quantum attack against SHA256 that reduces the brute force search space from 2^256 to 2^128, but that wouldn't really break the Bitcoin protocol. The ECDSA quantum vulnerability, however, would make ECDSA essentially useless.
Put this on a bootable usb with ubuntu or something and run it against the drive in question. Let it run overnight, and in the morning, you may find yourself with a windfall.
Here's the thread with more info: https://bitcointalk.org/index.php?topic=25091.0
After it runs, it will create a wallet.dat file that you will load with bitcoin-qt. If it works and you have the private keys, I would recommend exporting them into a better format, like an electrum or armory wallet.
http://bitcoin.stackexchange.com/questions/14260/negative-ba...
The prevailing experience is that yes, you can transfer, but you may have a 4-6 week wait.
It's a much different story these days. You can transfer $100K out of a brokerage faster than you can get $100 out of Mt. Gox.
Unfortunately I can't count myself in that bracket.
Sad times.
It's equally probable that people are going to laugh their heads off in a few years that people were selling their coins at $300. I mean it was ridiculous to us that the $30 coins were selling at $250 in April.
I am actually surprised there are so few people who posted on the poll with 100+ Bitcoin.
I sometimes invest on Just-Dice and plenty of people have thousands of Bitcoin to throw around, a lot of these people are developers with a passion.
Don't care about Bitcoin and absolutely sure I cannot predict what it will do in the future. It's outside of my focus.
But perhaps I just screwed up the poll.
I sold 5 coins at the first peak of $31/BTC. Thought I was pretty damn sly for getting out ahead of the following crash ($8/BTC). Joke's on me! I've now lost out on $1230 and counting.
And if I was you, I'd do myself the favor of not torturing myself about what could have been.
Incidentally, I also developed a Bitcoin Twitter ticker. If anyone would like to keep up with hourly prices via Twitter, I suggest that you check it out.
http://twitter.com/bitcoin_ticker
amagimetals.com
goldsilverbitcoin.com
I fixed up my house with a Lowe's giftcard bought with btc:
gyft.com
EDIT: Here's what your poll looks like as of t=35min:
▆▁▁▁▁▁▁▁▁▁▁▂
Leftmost bar is 0-5BTC. Rightmost bar is 100+BTC. Oh look, now we know basically nothing about the two most interesting ranges.
EDIT2: As of t=44min: http://www.wolframalpha.com/input/?i=bar+chart+154+21+26+15+... ... Pretty hilarious.
[1] http://blockchain.info/charts/balance?address=1DkyBEKt5S2GDt...
Where's my "just here to say I bought bitcoin before it was cool" option?
One potential solution to your problem is to do something like: sell Y% of my coins everytime the price increases by X%. An example would be sell 20% after each 50% rise (semi bullish plan. I also made those numbers up, don't consider them as specific advice).
:(
I fully understand the risks involved. Heck, my Economics degree makes me 1% more qualified than most people here to talk about how bubbles work.
If I'd bought BTC, I'd have been more worried about technical problems. I don't claim to understand the system in depth, but I know that crypto-fails happen all the time.
If an exploit is ever discovered, I wonder what we'd do with all that surplus bitcoin mining hardware?
Bitcoin can feel like a cult sometimes, something I am ashamed of.
Also telling everyone to buy just a little reeks of pump and dump.