Quote from: McMillan on December 25, 2013, 09:19:13 PM

Quote from: nonplussed on December 25, 2013, 10:41:02 AM

Quote from: CryptoPhilanthropist on December 25, 2013, 03:20:52 AM

Imagine when 2,000 years from now, some alien civilization uses its advanced technology to reverse engineer all the private keys and take the BTC. Wink

2000 years! Quantum computers will probably exist before then, and this is the sort of problem they eat up. Then again, they've been fifty years away for the last fifty years...but we're really close I promise!

Come to think of it, the fear that quantum computers can find private keys ought to harm confidence in cryptocurrency once it becomes feasible that the government might be there already. It's totally going to happen, it's just a matter of time. I know cryptography for the purposes of secure communication will simply move to symmetric algorithms with quantum key distribution to preshare the key, but I wonder how cryptocurrency will adapt. RSA being broken sorta breaks their entire model.

I often hear about the quantum computer threat, but still I haven't heard about what exactly quantum computer could do with modern cryptographic. Is it really such a threat, and if it is, wouldn't it be a threat not only to Bitcoin but to all modern world (like password bruting etc)?

Yes, you are right. The only problem is have enought reliable qbits in quantum computer linked together. As the qbits rise, the only defence is moving from Sha256 to Sha512 and higher before quantum computers with more qbits can be operated. I believe current experimental quantum computers use few qbits (4?), but for breaking Sha256 you need about 1000 qbits linked together long enought