The WarpWallet Challenge | Hacker News Reader

The WarpWallet Challenge

keybase.io

33 pointsok_craig14 comments

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Is this an underhanded plot, to get people to drain all brainwallets with 8-character passphrases?

Ohhh nice idea.

It doesn't seem difficult to generate all 8 character alphanumeric strings, but the 30 seconds it takes to generate the scrypt hash is the real challenge here.

218 trillion combinations. Roughly 69 million years to generate hashes on even half of that space.

Essentially, you need to find a hole in the algorithm, right?

What I mean is, there's no identifying information except that the wallet has 10BTC in it. Even if you could generate all the addresses at once, there's no way to know which one is the right one!

Except that they gave you the address. The trick is to figure out the private key.

At 1000 addresses per second (probably wayyy to high) it'd take 6919 average Gregorian years[1] to check all possible passphrases.

1: https://www.wolframalpha.com/input/?i=%28%28%2826%2B26%2B10%...

It looks like it's taking 20-30 seconds to generate one (250,000 turns of scrypt). You'd have to spin up 20,000+ instances to even get 1000 per second.

Hardly, for the earlier challenges I managed to hit ~50 a second with native code on a core i7. Missed out on winning any of the smaller challenges though though.

I don't think it's worth my time unless I managed to find enough hardware to do at least 100k attempts a second. Scrypt is executed on the CPU and the PBKDF runs on the GPU, then the GPU sits around and waits for the CPU to get it's job done before XORing the results. I considered making a pool, but there's no way of knowing if people are being truthful when submitting solutions.

It's a pity scrypt is designed to be hard to implement on hardware, or I'd have a crack at it with some FPGAs.

How'd you get the crypto_scrypt() call to go so fast?

one call to crypto_scrypt takes about a second on my machine. The pbkdf2 is the fast part. I'm using the crypto_scrypt from here: https://github.com/keybase/triplesec/tree/master/contrib/scr...

I just used pieces of John the Ripper and threw together something that worked.

BS alert...

Haha, I actually made this, indirectly!

http://crypto.stackexchange.com/questions/11786/a-key-deriva...

Shoutout to Max Krohn for actually asking though :)

Thank you for your construction. Cleaner than the one I dreamed up.

Nice, somebody already built a solving tool: http://gen.co:4567/

...how on earth did you find that? I only sent the URL to one other person, and your name is definitely not Calvin o_O

In any case, that definitely won't work. I'd run out of hard drive space on the server it's running on before it got close to being solved.

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