From Bell’s theorem to the device-independent quantum information scenario

Bell’s theorem proved the existence of quantum correlations with no classical analogue. After reviewing this fundamental result, we show how Bell non-local correlations are the crucial ingredient for device-independent quantum information applications. In this paradigm, devices are seen as uncharacterised quantum black boxes processing classical information and protocols are built without requiring any device modelling. This device-independent property guarantees that the protocol performance is self-certified and, in particular, provides the strongest form of quantum security.