How Entanglement-Generating Satellites Will Make the Quantum Internet Global

http://www.technologyreview.com/view/532216/how-entanglement-generating-satellites-will-make-the-quantum-internet-global/

by macovich50 • 12 years ago

27 14 12 years ago

technologyreview.com

DennisP2• 12 years ago

Does this have any use besides encryption? Because strong encryption already exists without all this.

jameskilton• 12 years ago

This has nothing to do with encryption. This is building an instantaneous global communication network using quantum entangled particles. One benefit, at least as far as we understand this phenomenon, is that the transfer of state between two entangled particles is untappable, making it the most secure communication medium we know of today without requiring any encryption at all.

That understanding could, of course, completely change at any time.

_sword• 12 years ago

instantaneous global communication network

Unfortunately that is not true. The transportation of information is still limited by the speed of light as you cannot transmit causal information via the collapse and subsequent measurement of the states of entangled particles.

http://en.wikipedia.org/wiki/No-communication_theorem

bdamm• 12 years ago

Allow me to change your understanding then. Quantum entanglement does not allow faster than light transmission of information.

exch• 12 years ago

[unsubstantiated armchair physics ahead]

One benefit of this approach I can see is that you don't, in theory, need transmitters and receivers to be in line of sight for a clear signal. If you are doing standard radio transmissions, it helps if there isn't a planet between you and the transmitter. With entanglement equipment on both ends, this is irrelevant.

You will also not be bothered by signal degradation. The real head-scratcher of quantum entanglement lies in that it works over any distance. The 'transfer' of state between particles is identical, whether the twin is sitting 1 meter or a million light years away.

But as the other commenters mentioned, you are still very much bound by the speed of light. So propagating state changes between entangled particles separated by 1 light year, will still take 1 year.

andrewljohnson• 12 years ago

Quantum computers are devastating to a lot of encryption, maybe moreso than we can yet demonstrate. I think crypto will evolve, and what we consider secure today will be as compromised as WW2 crypto is today.

DennisP2• 12 years ago

Not so much to symmetric encryption, effectively it halves the key length. And I don't think quantum links really substitute for public key encryption.

trhway• 12 years ago

Entanglement is set to become a valuable resource that is likely to be bought and sold, much like oil and gas today

now i know what will supplant bitcoin. Quantum ASIC entanglement miners - that is the future! Like with wine, the older the entangled ensemble, the more pricier it will be.

amelius• 12 years ago

I'm curious: what exactly makes a photon lose its entanglement? Is it an interaction with an atom (electron or nucleus)? If so, how can entangled photons even propagate through matter (fiber glass or the atmosphere) without becoming de-tangled? Or is this a special kind of interaction?

How Entanglement-Generating Satellites Will Make the Quantum Internet Global

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