Researched
Quantum Key Distribution
Eavesdropping-proof key exchange using quantum states: shown by satellite over more than a thousand kilometers in 2016/17.
Open in the interactive tree →QKD (idea: Bennett and Brassard, 1984) exploits that measuring quantum states disturbs them, so eavesdropping shows. China launched the satellite Micius in 2016 and in 2017 demonstrated key exchange and entanglement over 1,200 km and an intercontinental Beijing-Vienna video link. There are fiber networks with QKD (Beijing-Shanghai), but the NSA and many agencies prefer post-quantum cryptography because QKD needs special hardware.
Prerequisites
- Quantum Mechanics1925
- Information Theory1948
- Laser1960QKD sends single photons from laser-based sources over fiber and free space
- Communications Satellites1962
- Bell Test of Entanglement1964Entanglement-based quantum key distribution rests on the Bell test idea
Unlocks
- Quantum Internetopen