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Quantum algorithms conquer a new kind of problem

quantamagazine.org

21–30 of 35 posts

Re: Quantum algorithms conquer a new kind of problem

#22
post #3

Will quantum computing destroy blockchain and classical encryption algorithms as we know? So there will be a need for quantum blockchain and quantum encryption.

> Will quantum computing destroy blockchain and classical encryption algorithms as we know?

Short answer: the currently popular ones? Yes. All that we know? Probably not. See eg: https://ieeexplore.ieee.org/document/8967098

Re: Quantum algorithms conquer a new kind of problem

#23
post #3

Will quantum computing destroy blockchain and classical encryption algorithms as we know? So there will be a need for quantum blockchain and quantum encryption.

Classical asymmetric encryption algorithms like RSA and ECDSA (which Bitcoin uses) can be easily broken by a quantum computer. Brute-forcing symmetric algorithms like AES gets a speed up on a quantum computer, but not enough to consider the algorithms broken.

Oh cool, can you tell me who has successfully and easily achieved this result?

Re: Quantum algorithms conquer a new kind of problem

#24

Earlier quoted context omitted.

Classical asymmetric encryption algorithms like RSA and ECDSA (which Bitcoin uses) can be easily broken by a quantum computer. Brute-forcing symmetric algorithms like AES gets a speed up on a quantum computer, but not enough to consider the algorithms broken.

Oh cool, can you tell me who has successfully and easily achieved this result?

Peter Shor; though whether easily, I can't say for sure. https://en.wikipedia.org/wiki/Shor's_algorithm

Re: Quantum algorithms conquer a new kind of problem

#25
post #24

Earlier quoted context omitted.

Oh cool, can you tell me who has successfully and easily achieved this result?

Peter Shor; though whether easily, I can't say for sure. https://en.wikipedia.org/wiki/Shor's_algorithm

The previous commenter was being sarcastic, due to the use of the "easy" word (there is no implementation of Shor's algorithm yet that comes even near outpacing the classical version)

Re: Quantum algorithms conquer a new kind of problem

#27
post #3

Will quantum computing destroy blockchain and classical encryption algorithms as we know? So there will be a need for quantum blockchain and quantum encryption.

Classical asymmetric encryption algorithms like RSA and ECDSA (which Bitcoin uses) can be easily broken by a quantum computer. Brute-forcing symmetric algorithms like AES gets a speed up on a quantum computer, but not enough to consider the algorithms broken.

Bitcoin doesn't use them in a way that'd let you completely break it; the asymmetric keys aren't broadcast until someone does a new transaction with them, so you can't fake one for a wallet you've never seen the public key to.

Re: Quantum algorithms conquer a new kind of problem

#28

Earlier quoted context omitted.

Classical asymmetric encryption algorithms like RSA and ECDSA (which Bitcoin uses) can be easily broken by a quantum computer. Brute-forcing symmetric algorithms like AES gets a speed up on a quantum computer, but not enough to consider the algorithms broken.

Bitcoin doesn't use them in a way that'd let you completely break it; the asymmetric keys aren't broadcast until someone does a new transaction with them, so you can't fake one for a wallet you've never seen the public key to.

How is the transaction signature verified without the public key? This link seems to indicate spender public keys are inside of the transaction: https://bitcoin.stackexchange.com/a/102667

Re: Quantum algorithms conquer a new kind of problem

#29
post #3

Will quantum computing destroy blockchain and classical encryption algorithms as we know? So there will be a need for quantum blockchain and quantum encryption.

I'm surprised there aren't quantum blockchains already.

> I'm surprised there aren't quantum blockchains already.

There are:

> https://www.quantumblockchains.io/

> https://quantumblockchaintechnologies.co.uk/

:-)

Re: Quantum algorithms conquer a new kind of problem

#30
post #8
post #3

Will quantum computing destroy blockchain and classical encryption algorithms as we know? So there will be a need for quantum blockchain and quantum encryption.

Post-quantum cryptography is a thing: https://en.wikipedia.org/wiki/Post-quantum_cryptography

Until it’s not. Nobody has proven any of these schemes to be secure against quantum attack. Post-quantum (today) just means that nobody has proven that the problem is equivalent to a problem that quantum computing can solve efficiently. This article is about LWE being proven breakable. Others will follow. The security of these schemes rests mostly upon the lack of researchers that understand them and quantum computing well enough to approach an equivalence class proof. Example: elliptic curve isogenies.
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