Bitcoin Forum

https://i.imgur.com/rZUQd.jpg

Proof is here. Clearly the system is broken. Image is from http://www.bitcoinmonitor.com/.

Are you sure it is the same person/address? AFAIK, this could happen at any time due to the nature of the hashing process, it just usually doesn't...

You clearly have no idea how statistics work do you huh?

Hey I bet you'll probably also believe Derren Brown figured out how to throw heads 10 times in a row? http://www.youtube.com/watch?v=X1uJD1O3L08

7 in a row though, when the average time between is 10 minutes? The chance of it happening randomly is infinitesimal. Someone is clearly gaming the system somehow.

you don't have to break (=find collision) it entirely, just a few first bytes :)

i always thought the proof of work bitcoin uses is kind of weird...

clearly you fail

I've seen clusters like these before. I never started an alarmist thread claiming 'hacks' though, because I understand gaussian distributions and probability.

Time for a statistics refresher course, imperi.

Why him?

If I had special hashing powers, I'd distribute my blocks around different places, to different accounts, so nobody noticed.  8)

Imperi, I am Disappoint.

Where's the MS paint line? It's not as believable without the line.

Why only 7??? He should get 777 blocks if it was indeed hacked.

No.  It's statistics.  We've been at it 2 years, and there's gargantuan amounts of processing power behind this.  It was bound to happen eventually.


Finding a collision isn't breaking SHA256.  Breaking SHA256 (or at least, any manner of breaking that would matter to us) is finding a FAST and EFFICIENT way to find a collision, other than brute forcing.  There is no way to do this that is currently known, and it's stood up to many many cryptographic tests and analysis, people trying to hack it for years.

Eventually = right after a series of high profile hacks. Interesting.

either he wants to milk it a bit longer or his algorithm is not 100% sha256 hack but considerably more efficient than brute force used by conventional miners. maybe some statistical methods or something, i dont know but its not proven to be impossible afaik (or gimme a link pls)

imperi, stop trolling.

Hrm, a huge amount of publicity bringing some heavy computing power to the stage, increasing the odds of this happening?  Interesting.

well its different when you just work for your guaranteed wages and when there is a instant free big money floating, people could improve in their skills considerably with the right motivation.

However this is most probably a supercomputer working for a short time. Or more probably a good luck.

Man, that would be such a waste. If I had special hashing powers, I'd make hash browns all over the place. I'd make a bed out of them and then I could wake up in the middle of the night and snack without even leaving my nice warm bed. Oh man that's always been my dream.

Also, I'd make a car out of corned beef hash so I could drive down the road and make people hungry, because obviously the motor would use hash as fuel and the exhaust would smell good or something. I haven't worked out the specifics. I was thinking of making a plane out of hash, but it would obviously be too heavy. I would actually make two cars with drivers carved from hash and have them wreck at high speeds and then pretend I was just an innocent bystander. I'd run over after the crash and say "Oh god it's a mess. Meat strewn everywhere!" and start eating the wreckage.

I'd use my powers to create a secret closet full of hashish. Then I'd sell it, I guess, and buy something that I couldn't make with my hash powers, like pancakes.

Hmm. The hash marks would be a problem though, but I could live with that fault if I did truly have incredible hashing powers. I'd just buy new underwear every day with my hashish money.

Okay, I'll bite on the whole theory of "OMG HACKED" for a second. (And why it is wrong.)

Lets say for sake of theoretical argument it is true.

This is what I would do if I was some evil "Hax0r Do0d" that could produce blocks at will:

Strategy 1:
 
Stealth, produce blocks within a given distribution, probably driven by number generator that guarantees statistical analysis won't turn up an anomaly. Quietly wait while my blocks are verified, cue up 50btc orders on a few different exchanges and pull my funds into several different accounts. Rinse, repeat.

Strategy 2: (Which fits with the 'OMG HAX' part of this thread.)

Produce as many blocks as possible in a mad rush not only to authenticate what I'm already generating - but to stuff it down the throat of a few exchanges to cash out as soon as possible. Probability of detection - < HIGH >. Possibility of being caught and having my bitcoins 'stuck' at an exchange before I can flee - < HIGH >.

So, don't sweat the clusters.

Seriously.

Didn't japan just launch a computer that can do a quadrillion flops/sec?

yeah.  sha-256 gets broken and the first thing the guy does is steal 350 bitcoins.

HEY!  that could be almost $6000!

Isn't that 6x more than what the last hacker got?

I am intrigued by your ideas, and I would like to subscribe to your newsletter.

Why is it every morons wet dream for this currency to fail? Is it because you can't afford mining equipment? Is it because you can't afford to buy any coins? Is it that your TO LAZY AND WON'T WORK FOR THE CURRENCY SO YOU MIGHT AS WELL TRY TO DESTROY IT?

This thread is completely worthless until someone posts the mathematical odds of this happening (relative to how long bitcoin mining has been taking place and/or current difficulty rates and hashing power).

Yes, the promise of bitcoins, which in TOTAL, at their PEAK was worth less than 40 million dollars (Current Block # * Peak Price) is far more alluring than all of the bank systems relying on SHA256 encryption, all the SSH tunnels to be sniffed, government secrets, crime syndication, encrypted emails, and all the fame of being the one who broke it.

Also, nothing says this is the same person.  If it went to multiple addresses, it could very well be multiple people.  If it went to the same address, that could be one of the larger pools' addresses.  The conspiracy theorists in this forum are growing thick as mud.

Multiplication fail.

Also D- in foresight.

http://dilbert.com/strips/comic/2001-10-25/

Nine, Nine, Nine, Nine

ok since clearly you like conspiracy theories so much i will give you another one, my today's special! i invented this one just now while walking to work.

imagine how much people want to crack sha256.

before bitcoin: a bunch of professional security specialists. also criminals but they lack the skillz anyway.

after bitcoin: basically every single geek on this planet who is capable of reading a C source code of SHA256 implementation. they are not criminals mostly, or if some of them potentially are, they have other means to live and criminal activities are not their strongest suit anyway.

which is orders of magnitude more.

so here is the conspiracy theory: satoshi is basically a security expert of sorts who is testing his new method of brute forcing the security algorithms. basically all the geeks on this planet are raw computational power that tries to solve the SHA256 hash with their feeble minds. just like with mining, one by one they have very little chances to solve it, but working at once on the same task they might solve the block much faster!

we'll see how it goes :)

Forgive my ignorance, but how do you tell that one person got all those blocks? Couldn't it have been multiple miners, and what are the statistics of that happening?

You're off by a factor of 50.

current block# * peak price * 50 coins per block.

There's over 6.6 million coins out there right now.  Even at $15 that's $99 million.  At the peak it was ~  6 million * $30.  180 million.

yeah it's interesting, I wonder if it's possible to try and log the ip addresses of all block solvers? I would guess it's not in the client though since it violates privacy.

so no there is not way to detect it as long as the attacker uses separate addresses for each block.

Right, forgot that, still, paltry compared to the lure of all the above.

That'll only work 1/5th of the time then anyway, due to the rolling power outages they still have ;)

No.

I ran some quick numbers. If I'm correctly understanding the distribution, once the first block was found, the chance of finding the next 6 blocks in that time window was something like 0.0000002. However, this possibility has existed every time a block has been found. The chance of this streak happening at least once in 132000 or so blocks is greater than 99.7%. In fact, there is a very high chance that his has happened more than once. If I find the time, I could do an analysis of the whole block chain to see if this has happened before.

Is there an easy way to extract block timestamps from the chain?

BTCGuild found 5 blocks in 10 minutes or so. No random SHA256 crack unless they were stupid enough to share the wealth and ingenious enough to crack it... lol @ conspiracy theorists

If you evaluated the cdf of a gamma distribution with parameters 7 and 1/10min at 10min to get 0.0000002, and 1 - the pdf of the binomial distribution with parameters 132000 and 0.0000002 evaluated at 0 to get 99.7%, then I think it's correct.  I'm too lazy to calculate it, though.

Also, http://www.xkcd.com/882/ (http://www.xkcd.com/882/)

No they didn't. They launched a computed with the power of about 7% of the entire bitcoin network. No need to worry.

I'll buy them at a dollar a piece.

 ;D

Here's my favorite: http://xkcd.com/221/ (http://xkcd.com/221/)

My knowledge of statistics is a bit rusty, so I decided to look at the actual blocks. I ran a script to evaluate, from each block, how many blocks were found less than 420 seconds beforehand.

The record was twelve.

There were 358 cases of 6 or more (ie. 7 blocks in under 7 minutes). If we only look at recent blocks (>100000), we still get nine cases of this happening.

why do people keep commenting on imperis posts? arent you the same guy proposed that bitcoin will have a negative value in usd?
just void the post.