Device-Independent Quantum Key Distribution with Local Bell Test

Understand

Device-independent quantum key distribution (DIQKD) in its current design requires a violation of Bell's inequality between two honest parties, Alice and Bob, who are connected by a quantum channel.

• However, in reality, quantum channels are lossy, and this can be exploited for attacks based on the detection loophole.
• Here, we propose a novel approach to DIQKD that overcomes this limitation.
• In particular, based on a combination between an entropic uncertainty relation and the Clauser-Horne-Shimony-Holt (CHSH) test, we design a DIQKD protocol where the CHSH test is carried out entirely in Alice's laboratory.