"New and Hardened Quantum Crypto System Notches 'Milestone' Open-Air Test"

The race continues to develop post-quantum cryptographic methods. Chinese researchers achieved success when they conducted an open-air test of a new generation quantum crypto system. Unlike the previous iteration of quantum cryptography, the new system has a feature that allows for untrustworthy relay stations. However, the new and more secure quantum crypto system is said to be difficult to implement. It uses the quantum interference of single photons (light particles) to create secret cryptographic keys. These keys are indistinguishable despite their generation by independent lasers. A sender and receiver can securely communicate with each other using trusted lasers, even if the detectors performing the photons' quantum interference measurements are not trustworthy. Therefore, the cryptographic key can still be transmitted securely in the event that detectors at the relay station are untrusted or have been hacked. This article continues to discuss the successful testing of the measurement-device-independent quantum key distribution (MDI-QKD) quantum crypto system. 

IEEE Spectrum reports "New and Hardened Quantum Crypto System Notches 'Milestone' Open-Air Test"