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Large Bitcoin Collider Is Generating Trillions of Keys and Breaking into Wallets

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Re: Large Bitcoin Collider Is Generating Trillions of Keys and Breaking into Wallets

#21

Post by SomeStupidPoint »

csomar wrote: post #18
SomeStupidPoint wrote: post #13

Earlier quoted context omitted.

Small note, but 3,000 trillion is 3 quadrillion, not 3 quintillion. Which is their total, over a significant amount of time. The bitcoin network does over 3 quintillion (>3,000,000 trillion) hashes a second. So even if they were doing a significantly harder to compute hash -- they're still only a very small part of the computational power the bitcoin network is using. So it's probably already more effective to attack…

> So it's probably already more effective to attack wallets than join a mining pool. That's not how you make the calculations. The reason the idea was called stupid is because the math doesn't add up. My guess is that these 3 private keys had weaknesses in them. Even the probability that they were found by "luck" is way far off. Given merge mining is possible, I'd assume with some tweaking side-colliding + mining is…

I'm sorry, I'm not sure I understand your point: are you saying my math is off, given the claims of the article (ie, hashes computed, time spent, and compromises), or that the article is wrong because it's not that easy to crack?

Google found a SHA-1 collision (160 bit hash, same size but different method) in 9 quintillion hashes (plus some crypto work). The article claims they found a collision against 3 of millions of targets in 3 quadrillion hashes (likely plus some crypto work). Given the birthday paradox, it's not a priori impossible.

Could you explain why you don't believe their attack is mere hash collisions?

Re: Large Bitcoin Collider Is Generating Trillions of Keys and Breaking into Wallets

#23

Post by mankash666 »

chejazi wrote: post #15

Not sure their what their heuristics are for narrowing the search space, but there certainly are some good ones. For instance, early versions of blockchain.info's wallet generated private keys by reading an ARC4 stream that had been seeded with Math.random() calls xor'd with timestamps. Quite the circus!

If collisions exist in the hashing algorithm, how you derive the seed for a random number generator is pointless

Re: Large Bitcoin Collider Is Generating Trillions of Keys and Breaking into Wallets

#24

Post by awirth »

alphydan wrote: post #10
vbezhenar wrote: post #7

It seems suspicious. Bitcoin cryptography isn't broken, AFAIK, so chance to randomly break into any real wallet should be almost non-existent. I think, they either lying or exploit something different, like RNG weakness.

This explains the approach in more detail: https://lbc.cryptoguru.org/man/theory

This is confusing to me. The link describes narrowing the search space to ~136.17bit, but that is still far too large to be tractable. Do they get an additional birthday bound on that somehow? 68 bits would not be insane, but I don't really understand what's going on here.

I highly doubt they found a collision with a probability of 2^-136, unless they exploited some kind of bad RNG bug (in which case the probability is much higher, of course).

Re: Large Bitcoin Collider Is Generating Trillions of Keys and Breaking into Wallets

#25

Post by panarky »

api wrote: post #5
josst wrote: post #4

Earlier quoted context omitted.

Bitcoin is finite and one would expect the supply to become smaller over time thanks to keys being lost or owners dying and their accounts being inaccessible. In the long term guessing keys may be the only way to obtain new coins.

The new mining... This would basically make Bitcoin Keynesian, since coin stored in wallets would now decay with a given probability. So you would have to invest it at least a little to beat the decay (shrinkage) rate.

Bitcoin becomes unspendable and worthless when the private keys are lost.

But when you have the private keys, your Bitcoin doesn't "decay". On the contrary, it becomes more scarce, and therefore more valuable.

Re: Large Bitcoin Collider Is Generating Trillions of Keys and Breaking into Wallets

#26

Post by TheDong »

hrehhf wrote: post #11
TheDong wrote: post #8

Earlier quoted context omitted.

To receive anything, you must have an address (the public key). All coins (UTXO) are associated with addresses which must have private keys. It's impossible to only have a public/private keypair for the instant a transaction is being made because the UXTOs must be owned spendable by some public/private keypair while a transaction containing them is not immediately happening. You clearly don't understand what you're t…

You have ignored the difference between an address with has never spent anything and an address which is being reused. Since you know everything, why not address this directly? edit: Though unrelated to this article, here is a case where address reuse (and software bugs) led to vulnerable wallets: http://www.nilsschneider.net/2013/01/28/recovering-bitcoin-p...

An address which never spent anything can still be the recipient of a transaction.

Those are the addresses which are being attacked here.

Re: Large Bitcoin Collider Is Generating Trillions of Keys and Breaking into Wallets

#27

Post by TheDong »

panarky wrote: post #25
api wrote: post #5

Earlier quoted context omitted.

The new mining... This would basically make Bitcoin Keynesian, since coin stored in wallets would now decay with a given probability. So you would have to invest it at least a little to beat the decay (shrinkage) rate.

Bitcoin becomes unspendable and worthless when the private keys are lost. But when you have the private keys, your Bitcoin doesn't "decay". On the contrary, it becomes more scarce, and therefore more valuable.

You missed the point.

Once the primary way of gaining bitcoins is hacking wallets, the longer a bitcoin is behind the same private key, the longer that given wallet is a target.

Re: Large Bitcoin Collider Is Generating Trillions of Keys and Breaking into Wallets

#28

Post by ryan-c »

chejazi wrote: post #15

Not sure their what their heuristics are for narrowing the search space, but there certainly are some good ones. For instance, early versions of blockchain.info's wallet generated private keys by reading an ARC4 stream that had been seeded with Math.random() calls xor'd with timestamps. Quite the circus!

They're just doing a naive sequential search.

Re: Large Bitcoin Collider Is Generating Trillions of Keys and Breaking into Wallets

#29

Post by homero »

TheDong wrote: post #8
hrehhf wrote: post #6

It appears that they are finding the private keys for transactions that already occurred. Reusing an address is not part of Bitcoin's design and it was never intended for people to do that. By not reusing addresses (not reusing private keys) I think one would be immune to this attack. The article doesn't seem to have much detail; anyone have more detail on this? Edit: The details are in the URL posted by alphydan; it…

To receive anything, you must have an address (the public key). All coins (UTXO) are associated with addresses which must have private keys. It's impossible to only have a public/private keypair for the instant a transaction is being made because the UXTOs must be owned spendable by some public/private keypair while a transaction containing them is not immediately happening. You clearly don't understand what you're t…

There's actually a public key that isn't the address and it's revealed when spending

Re: Large Bitcoin Collider Is Generating Trillions of Keys and Breaking into Wallets

#30

Post by bigtimeidiot »

domador wrote: post #20

If this kind of attack is feasible, then maybe one should have several wallets and spread one's Bitcoin funds among these wallets, to dilute the risk. Maybe one wallet could be used just for receiving external transactions, but its funds could be immediately transferred to other wallets. Or maybe there are also weaknesses to this approach... I'm not currently a Bitcoin user, and ambivalent about Bitcoin's virtue, but…

>then maybe one should have several wallets and spread one's Bitcoin funds among these wallets, to dilute the risk

Sounds like Bitcoin is ready for the mainstream!

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