
Quantum Computers Are the Future Nukes of the IT World - rbanffy
https://www.nextplatform.com/2018/09/20/quantum-computers-are-the-future-nukes-of-the-it-world/
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eximius
No, they aren't.

You can't remotely disarm nuclear weapons or protect an entire industry by
switching algorithms.

They are a problem, and we should prepare for them, but they aren't
apocalyptic.

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hannob
Second sentence: "Now that the technology is moving from research to practice"

No such thing is happening. We're still in the state of "we're waiting for
someone to actually show that quantum computers can do anything at all faster
than a classical computer". Yeah, it's probably gonna happen in the not so far
future, yeah, there's progress. But saying anything is moving "to practice" is
absurd at this point.

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08-15
This is not news, it's an advertisement.

It's all fluff, vague nonsense about what quantum computers might supposedly
do, and mostly wrong. The implied assumption is that a quantum computer can
solve any NP problem in polynomial time, and that doesn't seem likely. And
then, all of a sudden, the purpose of this nonsense becomes clear:

> For its part, ISARA has developed a new method of creating a compound or
> hybrid digital certificate

This is followed by lots of marketing buzzwords. Disgusting, really.

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archgoon
Unlike nuclear weapons, a quantum computer is only dangerous if people _don
't_ know you have one.

There are a number of ways of dealing with the security issues posed by
quantum computers; most of them involve simply increasing the key length of
your encryption keys.

However, if people don't think you have a quantum computer, or you're able to
make it better faster than expected, they won't change their behavior and so
you have a fixed target.

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domparise
Quantum fintech is going to make blockchain fintech look like child’s play.

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madeuptempacct
You can't make statements like that without elaborating on what quantum
computing can possibly provide.

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domparise
Two examples off the top of my head: 1\. Instantaneous stock transactions from
anywhere in the world. (quantum communication/entanglement) Offers a
substantial RTT improvement on current trading systems.

2\. High frequency trading based on quantum prediction algorithms. (Quantum
information theory) May provide for HFT algorithms capable of producing
predictions based on an exponential number of information streams. E.g.
imagine making future investment decisions based on _all_ trades that happen
in a span of time.

@ me if you decide make a company to do either of these things.

~~~
siftikha
Entanglement doesn't allow communication.

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yters
It's not clear that quantum computers are even all that magical. At least we
know they are no more powerful than a Turing machine.

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amelius
Question: I get that QC can break _some_ cryptosystems, but can it break _all_
known cryptosystems?

~~~
yters
Nothing can break a one time pad, used for the super secure stuff.

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amelius
Yes, good point.

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ohiovr
Are ordinary ssh keys vulnerable?

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archgoon
If your ssh key relies on RSA, then yes, you're relying on the difficulty of
factoring numbers; which Shor's algorithm can perform efficiently. But only if
the quantum computer has enough qubits. The needed number of qubits needed to
factor is a multiple of the rsa key length. Unlike a regular computer, where
you can finagle two computers with 2 gigs of memory to work like a single
machine wiht 4 gigabytes of memory, so you can't just merge two 1024 qubit
computers to get a 2048 qubit computer. And we're a long way off to having
anything close to that.

The simplest solution is simply to increase the size of the key beyond that of
the most advanced quantum computer (which is essentially today's approach ;)
). Also, you just need to exchange a symmetric key; Shor's algorithm is a
special case, you don't get the exponential -> polynomial speedup[1] to
encryption algorithms in general. So once you deliver the symmetric key in a
secure way, using a quantum resistant algorithm, you can resume business as
usual.

[1] Though in brute force searches, you can reduce the effective key length by
2.
[https://en.wikipedia.org/wiki/Grover%27s_algorithm](https://en.wikipedia.org/wiki/Grover%27s_algorithm)

~~~
ohiovr
You can't have an an infinitely long key. Eventually the decripting process
slows everything down to nothing.

