Comment on South Africa and China establish record-breaking 12,900 km ultra-secure quantum satellite link.
NarrativeBear@lemmy.world 3 weeks ago
Very cool, I wonder if a quantum link like this needs a clear line of sight. What would be the limits of quantum communication like this? It would be amazing to be able to achieve real time communication between planetary bodies for example.
Quantum entanglement/teleportation does not mean information transmission exceeds the speed of light. You’re still limited to sending entangled particles to your destination following the laws of physics. You cannot transmit information via this phenomenon.
What you can use this for is transmission integrity. Where you will know if an outside observer intercepted your transmission then sent it on its way to the destination. This is more commonly known as a man in the middle attack (MitM).
Adversary in the middle is the updated terminology. Not just because sex, but also bots and AI.
Ooo thank you, I’m definitely out of date by now
I always imagined quantum entangled particles would be useful in information transmission. Probably not directly, such as the particles transmiting the information themselves, but in a way potentially vibrating a particle on one end and getting the same vibrations on the other end. Depending on the vibrations you deduced the information.
Obviously sending one of the entangled particles to another destination would be as slow as the fastest mode of transport.
But i wonder if we had a entangled communication device on either of the voyages probes if we would be able to send commands to them from earth with no lag in transmission.
vic_rattlehead@lemmy.world 3 weeks ago
This is not a “quantum entangled data link”, it is a regular radio data link secured using quantum computing to generate encryption keys.
LodeMike@lemmy.today 3 weeks ago
But why
febra@lemmy.world 3 weeks ago
Because you can use one time pad encryption which is theoretically unbreakable. Intercepting the photons used to generate these keys would instantly alter their state thus making them unusable.
LodeMike@lemmy.today 3 weeks ago
oh right one time pad.
It really does feel like you could do this in a better way, though.
rottingleaf@lemmy.world 3 weeks ago
I’ve read some weird paper about such an analog channel, where something quantum on both sides was used to create another analog signal used kinda as an encryption key. Stumbled upon it trying to understand some things about optics long ago.