Experimental Side-Channel-Secure Quantum Key Distribution

Quantum key distribution can provide unconditionally secure key exchange for remote users in theory. In practice, however, in most quantum key distribution systems, quantum hackers might steal the secure keys by observing the side channels in the emitted photons, such as the photon frequency spectrum, emission time, propagation direction, spatial angular momentum, and so on. It is hard to prevent such kinds of attacks because side channels may exist in many dimensions of the emitted photons. Here we report an experimental realization of a side-channel-secure quantum key distribution protocol which is not only measurement-device independent, but also immune to all side-channel attacks to the photons emitted from Alice's and Bob's labs. We achieve a secure key rate of 1.73 x 10(-6) per pulse through 50 km fiber spools.

Automated summary

Quantum key distribution provides theoretically unconditional secure key exchange, but in practice, quantum hackers can steal secure keys by observing side channels in emitted photons. This study proposes a side-channel-secure quantum key distribution protocol that is measurement-device independent and immune to all side-channel attacks. The experiment achieved a secure key rate of 1.73 x 10(-6) per pulse through a 50 km fiber spool.