Device-independent quantum key distribution

Understand

In this thesis, we study two approaches to achieve device-independent quantum key distribution: in the first approach, the adversary can distribute any system to the honest parties that cannot be used to communicate between the three of them, i.e., it must be non-signalling.

• In the second approach, we limit the adversary to strategies which can be implemented using quantum physics.
• For both approaches, we show how device-independent quantum key distribution can be achieved when imposing an additional condition.
• In the non-signalling case this additional requirement is that communication is impossible between all pairwise subsystems of the honest parties, while, in the quantum case, we demand that measurements on different subsystems must commute.