
World’s first quantum-cryptographic satellite network is likely to be Chinese - doener
https://www.economist.com/news/science-and-technology/21727889-quantum-cryptographys-early-birds-first-quantum-cryptographic-satellite
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samstave
The fact is that we have political circus in the US that will kill the nation
long term.

The Chinese have a 100 year plan for dominance they are working toward.

The only thing the US appears to have is a strong military and a current
monopoly on the available technologies.

In 100 years, china will likely dominate the globe.

~~~
hcurtiss
China is willing to displace 1.5 million people to build a dam. [1]

We are unwilling to hang powerlines. [2]

China is going to win economically. That usually also equates to militarily.

[1] [http://www.bbc.com/news/world-asia-
china-17754256](http://www.bbc.com/news/world-asia-china-17754256)

[2] Too many to cite, but for starters:
[http://www.baltimoresun.com/news/maryland/harford/aegis/ph-a...](http://www.baltimoresun.com/news/maryland/harford/aegis/ph-
ag-norrisvile-power-project-opposition-0616-20170615-story.html)

~~~
samstave
Yep, and this has been widely known for decades.

The fact that there was an article almost ten years ago titled "china invades
Africa" which talked about the Chinese resource grabbing in Africa illustrated
the long term plans.

The us political system is an utter joke, and we will lose the economy pretty
fast.

Oligarchs in the us can only think about five years out. I'd say the only long
term thinker in the us currently is musk, even with all his flaws, he is
building real systems of longevity.

Everything else is ephemeral.

~~~
nv-vn
Long term thinking isn't possible in the US because we have a democratic
government. The only 'solution' that would make it possible is to centralize
under one party and create an oppressive government that doesn't give a shit
about its people. I don't really know if that's what you are advocating for
here, but I think it's important to highlight that the reason China is so good
at planning ahead is because it will let nothing get in its way. Saying that
the 'us political system is an utter joke' makes it seem to me like you think
China's is somehow better, but I don't get how you can think that based on the
parent comment you're responding to. Should we be calling for the US
government to displace millions of people for every construction project?
Should we limit the rights of every minority (whether biological, religious,
political, etc.) and continue moving against their will? Should we ban access
to information which criticizes our government in order to stop political
dissent?a

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ythn
> This phenomenon depends on the fact, surprising but true, that particles
> with identical properties which are created simultaneously are entangled in
> a way that means one cannot have its properties altered without also
> altering the other, no matter how far apart they are.

This implies FTL communication, which is impossible. I thought entanglement
was more like if you cut a coin in half along the edge and then observed that
your half was heads, then you knew the other half was tails no matter how far
away. I don't see how this helps detect eavesdropping.

~~~
im3w1l
Imagine that I give you a magic piece of paper with two binary digits
(00/01/10/11) on it. I also keep such a paper for myself. If we both start by
looking at our first digits then those will mysteriosly match, but if we then
look at our second digits they will have just a 50% chance of matching.
However, if we both start by looking at the last digits, then those will
match, and our first digits will have a 50% chance of matching. If you and I
start by looking at different digits, then the digits we read are just
standard random bits.

The cool thing about this is that our magic paper will also work instantly
even if we are lightyears apart. However, if you decide to look at the last
digit and you see a 1, then that tells you nothing about me or which digits
(if any) I have looked at, so I can't send you a message with this paper.

~~~
ythn
Ah, so if I understand correctly, you could detect message eavesdropping as
follows:

1\. We agree ahead of time to always observe the first digit of magic papers
first.

2\. I send you a message that includes eavesdropping-detecting magic pieces of
paper

3\. We then compare what you measured as first digits to what I measured as
first digits

4\. If the digits do not match, it means someone eavesdropped on the magic
pieces of paper I sent and observed the wrong digits first.

But then aren't we back to the same secret distribution problem, where the
secret is which digit we should observe first on magic papers?

~~~
im3w1l
As you point out, that protocol is flawed.

Here is a protocol that works (BB84):

Needed:

* A way for Alice to communicate (classically) with Bob that can be read by Eve, but CANNOT be manipulated by Eve.

* A way for Alice to send magic paper (qubits) to Bob, that CAN be intercepted and manpulated by Eve.

Steps:

1\. Alice sends a bunch of magic paper to Bob.

1.5 Eve potentially intercepts the shipment and manipulates it.

2\. For every piece of paper, Alice randomly decides which digit to check. Bob
does the same independently.

3\. Alice and Bob tell each other over the classic channel, that Eve cannot
intercept, which digits they checked.

4\. They discard the papers where they checked different digits, and use the
rest to form a One Time Pad.

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divbit
It seems hard to find non-blockchain related/ ethical, crypto jobs in the US
which would lead to quantum cryptography type output.

