Reductions to IID in Device-independent Quantum Information Processing

Understand

The field of device-independent (DI) quantum information processing concerns itself with devising and analysing protocols, such as quantum key distribution, without referring to the quality of the physical devices utilised to execute the protocols.

• Instead, the analysis is based on the observed correlations that arise during a repeated interaction with the devices and, in particular, their ability to violate the so called Bell inequalities.
• Since the analysis of DI protocols holds irrespectively of the underlying physical device, it implies that any device can be used to execute the protocols: If the apparatus is of poor quality, the users of the protocol will detect it and abort; otherwise, they will accomplish their goal.
• This strong statement comes at a price-- the analysis of DI protocols is, a priori, extremely challenging.