Bitcoin Forum

Actually my question is how much time at 1 TH/s is needed to crack any of the top 10000 holding btc addresses?

what if someone start a pool to crack any of those keys?

someone can "protect" spliting holdings in a few accounts, but if only a key is cracked that  would hurt BTC very bad.

So, how much time is needed to crack any key? not a specific one, supouse The script keeps a bunch of keys in memory and with each iteration tries to brake any of them.

Thank you!

This question has been answered 999999999999999999999 times.

More than the universe life.

Bruce Schneier (http://quotes.vemod.net/post/88916030/if-we-built-a-dyson-sphere-around-the-sun-and)

I missed them. However a brute force attack would be much easied by the fact that the private key is a known number of characters. Moreover it would even not have to be really a brute force attack based on power of calculus, but just a check of the greatest number of possible private keys in the shortest time possible.

Only two characters. It is entirely made up of ones (1) and zeros (0), but there are 256 of them.


That is what the definition of "brute force attack" is, isn't it?

ie about 60 years from now.

Edit: if you believe Ray Kurzweil

Ray Kurzwiel has made futurist predictions but never saw the one about

I don't understand your comment. If you assume that private keys are NOT totally random (i.e. uniformly distributed), then it's not a brute force attack. I don't know how you can assume that though.


I didn't know he was into metaphysics.

P.S. I don't think anyone with a bit of sanity ever made such a prediction.

He's talking about 256 bit AES keys here, not Public/Private key pairs.  Asymmetric keys are weaker than AES keys in general (which is why they need to be much larger).  I'm not familiar enough with ECDSA though to make a judgement about key strength for bitcoin key pairs in particular.

I mean that the attack would be easied by the fact that a private key is made of a known, exact number of characters (34 I think), not one more, not one less. That limits much (compared to infinite) the number of possible combinations to test.

So? I am sure someone come up with an answer.

If i have to crack the private key of a specific address it will take more time than I can care about. But I am asking how long to crack any of the thousands of address with possitive balance.

That should be much more easy.

If there are 2 people in a room the prob. of the 2 people with the same birthday is like 1/365 but if i have 23 in a room the prob of 2 of them having the same birthday is 50,7%

Si the time consumed to someone finding someone's private key should be way to shorter than the age of universe

The question is how much shorter?

It "limits" it to an insanely large number.  A number so large that our star doesn't have sufficient energy reamining to COUNT to 2^256 much less brute forces keys.  Note: this assumes you could build a perfect computer (in the thermodynamic sense), capture the entire energy output of our star (and exterminate all life on our planet in the process), convert that energy with no loss, and build a large enough computer to use that energy, and keep the computer at roughly the background temperature of the universe (perfectly radiating waste heat).  If you did all that you could count to ~2^192 which is about 1/Quintillion of 1% of the way to 2^256.

So the answer is ... no.

However there are some non-brute force attack which (someday) may lead to an exploit.

1) If there is a bias or flaw in RNG that can be exploited it in theory could allow an attacker to narrow the search space.  By knowing the creator didn't use a range of numbers you can exclude them from the search and potentially brute force a much smaller keyspace.  Then again narrowing the search space from 2^256 to 2^190 doesn't really do you any good, even narrowing it down to 2^128 wouldn't be viable.  Still it is a theoretical exploit.  With true hardware and even quantum RNG becoming cheaper and accessible this may not even be possible in the future.

2) If a flaw is discovered in SHA-256 or RIPEMD-160 it "could" allow a faster than brute force attack attempting to force a collision.  The bad news is such flaws tend to take decades to develop from academic curiosity to real world attack vector.

3) Quantum computing potentially could make faster than brute force attacks on ECDSA a reality ... someday.  It would take an huge number of quibits (magnitudes beyond anything we can do today) to make it possible.  This also requires you to know the public key which remains a secret until coins are spent.  Of course funds could be moved to quantum resistant algorithms rendering this attack void.

Pay closer attention. He's talking about counting from 0 to 2²⁵⁶.  Just counting.  No encryption, no algorithm, no hashing, just counting.

If it is impossible to count to 2²⁵⁶, then clearly it is much more difficult than impossible to actually "crack" a private key via a brute force attempt regardless of whether you are attmpting to "crack" AES, Asymetric, or a simple hash.

Also note that as long as the address hasn't been used to send any bitcoins yet, the public key is unknown, so it isn't enough to brute force ECDSA to find out if the private key is associated with some bitcoins. For each iteration of the brute force attempt you would need to calculate the public key via ECDSA, and then calculate a SHA256 hash, and then calculate a RIPEMD hash, and then compare the result to a list of addresses that have bitcoins in them.

Human minds have a very difficult time comprehending VERY LARGE numbers.  The fact that you are comparing to 1,000, or 10,000 or even 10,000,000 addresses isn't going to make the brute force attempt possible.

Yep, it limits it to just a bit less than 2²⁵⁶ possible combinations.  Not infinite, but a large enough number that it doesn't matter that it isn't infinite.

No, it will take more time.

If it takes 1 second to make one attempt to crack one address, then making one attempt to crack 10,000 addresses will presumably take 10,000 seconds.  I can't see why making one attempt to crack two addresses would be quicker than making two attempts to crack one address.  Because you have to make more checks for more addresses, unless there's something I'm misunderstanding.

It depends a bit on the situation.

Imagine for a moment that it takes 10 ms to calculate the address from a given private key.
Imagine also that it takes 0.1 ms to look up that address in a database to see if it is a match.

Calculating 10 iteration of private keys and looking up 1 address each time is (10 x 10ms) + (10 x 0.1 ms) = 100 ms of calculation time + 1 ms of lookup time = 1001 ms
Calculating 1 iteration of private key and looking up 10 addresses is (1 x 10 ms) + (10 x 0.1 ms) = 10 ms of calculation time + 1 ms of lookup time = 11 ms

I am not sure why some of you say 2^192 and some say 2^256

assuming 2^192

p=1-(2^192/(2^192-1))^n

where

p = probability to find a key in 1 iteration
n = selected key space (the addresses with balance > 0

so
q=1-(1-(2^192/(2^192-1))^n)

q= probability of not finding a key in 1 iteration

j= number of iterations

P=1-(1-(2^192/(2^192-1))^n)^j
P= prob of find a key in j iterations

can someone find the j value to satisfy =
q=0.5
q=0.1
q=0.01
q=0.001
q=0.0001?

Waste of time trying this..

2¹⁹² is the approximate thermodynamic limit of how high a perfect computer could count if it could capture and use up all the energy that the sun will ever produce (leaving nothing for life here on earth).  It is used as an example to demonstrate just how large of a number we are talking about here.  The actual number of possible private keys is a bit less than 2²⁵⁶, demonstrating further how difficult a brute force attack is since 2²⁵⁶ is so much larger than 2¹⁹² which uses all the energy the sun will ever produce.

In actuality, there probably isn't a need to iterate through that many private keys.  The bitcoin address space is only 2¹⁶⁰ from the RIPEMD-160 hash that is used.  If we can assume that RIPEMD-160 results in an even distribution of addresses, then the number of iterations needed to encounter a collision will be much less than if the address space was 256 bits.  However, we are still talking about a number that is large enough to consider it futile to attempt.

Heck with all this hard maff stuff.  You can determine how long it will take just by doing it!

1) Go to this thread:  https://bitcointalk.org/index.php?topic=107172.0;topicseen (https://bitcointalk.org/index.php?topic=107172.0;topicseen)
2) Download the program
3) Enter all the public keys from this thread:  https://bitcointalk.org/index.php?topic=92423.0;topicseen (https://bitcointalk.org/index.php?topic=92423.0;topicseen)
3) Run the program
4) Report back here when you crack one of the richest keys!

Very cool. Thanks.
Will phone back if I find any coin in the deep space.

ty!

Lolz.  I got to remember that next time Burt.

You cannot crack a private key by brute force, there are not enough atoms available.

It is possible one day people will find failings in the algorithms, but they would have to break more than one.

Ohmygod! This thing found thousands of public/private key combinations in a few hours on a couple of old puters of mine.
It's all in the text files it created!  :o
I just imported a private key on blockchain.info and it got accepted (it was empty, luckily for the owner).
 
Now the point is: if it is possible to import all of the private keys that this proggie finds all at once in a wallet, this may well be the beginning of the end of Bitcoin. In any case I see this as an huge as an ocean BTC security breach.

Please anyone in the know tell me something. I am quite terrified and wondering if it is the case of getting out of Dodge-BTC at full speed.

That's sarcasm, right?  You can't possibly have been on bitcointalk.org long enough to have over 900 posts and actually believe anything you just wrote.

The program you are running randomly generates private keys.  You can generate as many private keys as you want.  Generate thousands.  Generate hundreds of thousands. Generate millions.  It doesn't matter, they all are going to be empty, because nobody else has generated/used any of them yet.

The one you imported was empty because you haven't sent/received any bitcoins there yet.  It isn't "luckily for the owner".  You are the owner.  You just generated a brand new private key that nobody else has ever generated before.  You are the first person to use it.  Actually, you just generated thousands of brand new bitcoin addresses that nobody has ever used before.  You are now the proud owner of several thousand brand new, unused, empty bitcoin addresses.  What will you be doing with them?

Ok. Then since it's so pointless, could anyone suggest a way to import all these private keys at once in a wallet?

I'm not aware of any tool in common use that will allow you to easily import a list of thousands of private keys into a wallet.  There probably isn't much use for one.  It shouldn't be very difficult to write though.  What wallet are you using (Electrum, Multibit, Bitcoin-Qt, blockchain.info/wallet )?

For 100 BTC fee, I'd probably take the time to write up a bulk private key import tool for you. Although if what you are looking for is collisions with addresses that have bitcoins stored in them, why bother importing all the empty private keys?  Wouldn't it be better to have a tool that will scan all the addresses and output a list of the addresses that actually have bitcoins associated with them (if you ever actually found any)?  Then you could just import those private keys.

This is the number of seconds since the big bang 13.7 billion years ago
432043200000000000  (60*60*24*365*13700000000)

This is 2^256
115792089237316195423570985008687907853269984665640564039457584007913129639936

2^256 / 432043200000000000 will give the number of attempts per second since the dawn of time to try all the combinations in a brute force attack.

If you can find a computer capable of testing 7778752908943661823213959165079225774884848073919 hashes a second and you manage to live for 13.7 billion years you might stand a chance.

Best of luck  ;D

It's just that I don't feel to be particularly lucky with chances, and I am terrified that someone casually finds my wallet after years that I mine.

BTW: the deep space proggie would be much better if it saved just the keys of filled wallets checking the blockchain.

Sell them to new forum members  :D

Your fear is unfounded.  There is no reason to be terrified of this, but it seems that nobody is going to be able to convince you.

Still not.. sure.. if.. serious.  Serious?

The point of my sarcasm above "go for it and see if you can do it" is that you will NEVER find someone else's private key using a brute force attack.  NEVER.

You can make your suggestions for improvments in the deep space program in the thread for that program.

2^256 is such a mind bogglingly huge number that even if you were to design the perfect computer the laws of nature that restrict information travelling faster than speed c (or the speed of light) would mean even that perfect computer would take thousands of years to crack it. (don't expect this type of computer for sale in radio shack any time soon)

Your paranoia is unjustified  :D

I'm happy to be reassured by the experts.
I must have been influenced by all those films where the thieves always find a way to open a safe.

It will be far easier for the thief to gain access to your computer and look at your private keys then it will be for them to use brute-force calculation to find your private key.

If somebody wants to steal your bitcoins, you need to be MUCH more concerned about them opening the safe where you are storing them than concerned about them figuring out your private key without looking at it.

If you put your private keys in the best safe ever created, and then sent that safe on a rocket into space on a trajectory that would put it in orbit around the next closest star...

It would still be faster and easier for a thief to travel to that star, crack open the safe, and come back to the earth to spend your bitcoins than it would be for them to guess your private key using a brute-force attack.

I always like these analogies. ;)


I quite don't know how this bias is labelled, but we tend to fear things that we know the particulars of more than the things that are out of our focus, regardless of specific probabilities. In these situations, I try to focus on numbers and try hard to grasp the meaning of them using familiar analogies.

Note:  Given the amount of energy that would be required to brute force a private key (or set of private keys), Not only would it be faster for the thief to travel to the star and back, it would also be cheaper.  It would cost less to design, build, and launch a rocket capable of interstellar travel with all the resources necessary to sustain life for the round trip, than the cost of the energy necessary of have any chance at all of cracking a randomly generated private key.

So clearly, it will be more cost effective and time effective for any thief to find a way through whatever security you think you've put in place to gain access your wallet than to try to brute-force crack private keys.

it is a waste of time only thinking it

Let's put this in simpler terms. You'll be better off mining Bitcoins than cracking privatekeys with the proposed resources. There is an infinitely close chance to mine an amount greater than the richest address in the blockchain, than cracking the private key associated with it.

Practically forever

More than the universe life.

---

 A long, long time.