Topic: Will quantum computing kill crypto? - page 5. (Read 9112 times)

Ok I understand, I guess it's always hard to predict the capability of future technology but even so sounds like it wouldnt be an issue/is easily overcome.

Thanks for helping me clear that one up in my own head!

Bitcoin is inherently resistant to quantum computing as it does not disclose the public key, instead it hashes it twice! So the attacker literally has no chance to 'derive' the private key even armed to a super quantum computer like in a science fiction.

So far so good, BUT when one 'spends' his wallet, eventually has to disclose his/her public key and if s/he accidentally tries to use the same address again, well, from here on the alarming flags should be raised if there are powerful enough QCs commercially available.

Note:
In the limited interval between the time of the spend Tx even for the brand new addresses, until they get confirmed, there is a window for the QC attack to compromise the private key and generate another transaction with higher fee and priority and steal funds, taking advantage of this window needs very huge QCs to break the code very fast, not like few days, but few seconds. Such QCs not likely to be built ever.

Anyway, when it comes to upgrade, there will be a soft fork, implementing new address types and thus new cryptographic algorithms. After  the fork, all new transactions will be safe in heaven, the only weakness will be the elder UTXOs with used addresses, though it will be the holders' responsibility to renew their wallets asap.

No. If quantum computing does become a reality, the time taken to bruteforce a private key to a public key will decrease substantially but not to that much magnitude.

Yes.

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I am not currently aware of any development on such an algorithm for now. With reference to my initial post, the security risk of this can be easily mitigated. As long as people do not reuse addresses, it is quite hard for anyone to profit using a quantum computer. Speaking of profits, the cost of operating one is quite expensive and not everyone can have their hands on it.

Great resource! Thanks for sharing that. So I take it that if post-quantum cryptography is already being worked on in order to be prepared then that extra layer of security can be written into the Bitcoin code, even that far down the road?

Panic over I guess 

It is not the way you put it. We have quantum resistant cryptographic algorithms out there, already:
https://en.wikipedia.org/wiki/Post-quantum_cryptography
I'm specially a fan of this one:
http://ieeexplore.ieee.org/document/6337933/?reload=true

Quantum computing is too immature to be considered a threat for at least this decade and when it happens to be ready, we are ways ready. Just don't panic.

With the steps forward that quantum computing is making will it mean the end of crypto as we know it once quantum computing become a reality?

I mean it effectivly makes encryption useless, someone with a quantum computer could just brute force a private key from a public key in no time. This will kill every crypto currently out there.

Do you think we will see new quantum cryptos released once the technology is ready? Or do you think Bitcoin will adopt a new layer of quantum security if that is even possible?

I'm by no means an expert on the subject but unless the good guys get their hands on some form of quantum computer before the bad guys it kind of puts a ticking timer on the whole crypto industry. That's if an extra layer of quantum encryption can even be implemented in some way for Bitcoin.

If not, then I guess we better time it just right and get the f**k outta here at the right time.

Thoughts?