Score:2

What is the current situation of quantum computers?

us flag

Like other research areas of cryptography, quantum computing consists of hidden and open fractions. Apparently, we can't say certain things about governments' capabilities where academical or industrial developments in quantum computers relatively public.

In this context, what is the current developments in quantum computers? Is it serious threat to current cryptographic algorithms in the near future?

NB_1907 avatar
us flag
Would you give more details? Why quantum computers can not be competitive in cryptanalysis?
fgrieu avatar
ng flag
[reposted with update] The title of the question asks for the _current situation_. That one is easy, at least for what's open: quantum computers are unable to compete with a computer system based on a [microprocessor of the 1970's](https://en.wikipedia.org/wiki/Intel_4004) when it comes to cryptanalysis. Taking integer factorization as a benchmark, the highest claim is 21=3x7 using Schorr's algorithm, or a 6-digit integer using algorithms that can't scale (see [this](https://crypto.stackexchange.com/a/59796/555), skipping the stunts at start). Things are similar for combinatorial problems.
kelalaka avatar
in flag
How many Qubits actually built? Or [they are making some fun](https://quantumcomputing.stackexchange.com/q/9204/4866)? [How many Q-bits are needed](https://security.stackexchange.com/a/242021/86735). How much time is needed for the Grover's per setup(query); $~2^{64}$ for AES-128?
Score:7
ru flag

Opinions vary. Given any time period between "within 5 years" to "never", you can likely find a credible technical individual who holds to that belief. A good survey of the range of opinion (at least as of 2019) was done for the Global Risk Institute by Michele Mosca and Marco Piani.

kelalaka avatar
in flag
Well, actually, the scientists had many bad predictions over time. Some deliberately, some with lack of understanding, some had good but not enough arguments to see it. I remember that during early 2000 they predicted that some small scale, like 100s Q-bits ( not DWave) will be in use, yet where we are.
kelalaka avatar
in flag
[Einstein vs Bergson](https://www.abc.net.au/radionational/programs/philosopherszone/science-vs-philosophy-and-the-meaning-of-time/6539568), Even some says that due to debate's position, Einstein did not win Nobel Prize for Relativity.
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