
Google Achieves Quantum Supremacy. Is Encryption Safe? - ItsTotallyOn
https://www.tomshardware.com/news/google-quantum-supremacy-encryption-safe,40489.html
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neonate
The FT piece the article refers to is here:
[http://archive.is/ZLiUp](http://archive.is/ZLiUp)

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ahelwer
"Researchers from Canadian company Krypterra believe that we’d need 2,953
logical qubits to break AES-128 and 6,681 logical qubits to break AES-256."

Grover's algorithm only gives a sqrt(n) speedup for breaking AES, so the
number of bits is irrelevant; breaking 256-bit AES on a quantum computer would
take as much time (or gates, rather) as breaking 128-bit AES on a classical
computer.

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api
QC is really only a risk to RSA, DH, and elliptic curve, and maybe to small
hashes and key sizes. I'd say if your symmetric stuff is bigger than 128 bit
you only have to worry about asymmetric crypto.

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darkmighty
[https://www.scottaaronson.com/blog/?p=4317](https://www.scottaaronson.com/blog/?p=4317)

Scott's Quantum Supremacy FAQ

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septafree
Almost mandatory link for any informed quatuom computation discussion:

[https://www.scottaaronson.com/blog/](https://www.scottaaronson.com/blog/)

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rcardo11
That paper just threw a mind-blowing title and abstract but the task they were
solving was too narrow. No general-purpose quantum computer for the moment.

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kevinwang
What the heck is a general purpose quantum computer??

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api
Somewhat of a tangent but: a big driver for QC investment is breaking
encryption for military purposes. We already have encryption that is not
believed to be vulnerable to QC, and there is a ton of crypto R&D to make it
faster and more practical (e.g. smaller keys and signatures).

I wonder if that won't kill some QC investment.

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Xcelerate
Has Google officially announced QS yet, or is this all based off of leaks?

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MiroF
Leaks but it's probably true leaks

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hartator
> Google Achieves Quantum Supremacy

Is it another careful crafted academic lie or is it real this time?

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abdullahkhalids
There are two subgoals towards the creation of quantum computers

* quantum supremacy: this is a scientific goal. This can be achieved by building a quantum device that can solve some, possibly useless, computational problem faster than a classical computer. The Google team claims to have done so. For scientists, wondering whether the extended Church-Turing thesis is true or not, the Google result is a significant result. It provides some evidence that the thesis is not true.

* quantum advantage: this is a technological goal (even though it also has scientific implications). This is about building a quantum device that actually solves useful computational problems (like breaking encryption) faster than a classical computer. We are not there yet.

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mehrdadn
> (extended) Church-Turing thesis

I'd take out that parenthesis, it's misleading. The Church-Turing thesis is
about computability, whereas the "extended" one is about complexity. They're
quite different beasts despite the similar name, and QS would really only be
evidence against the extended version.

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abdullahkhalids
Agreed and fixed. Thanks.

