Final Report Summary - QITBOX (Quantum Information Theory with black BOXes)
QITBOX aimed at developing the device-independent framework for quantum information processing in which devices are seen as quantum black boxes that produce outputs upon receiving inputs. The most important scientific outcomes resulting from QITBOX were: (i) novel methods to characterize quantum correlations, often using concepts from other areas such as algorithmic information theory or convex optimisation; (ii) ultimate limits on randomness generation using quantum systems; (iii) novel protocols for certified randomness generation of secure key distribution; (iv) scalable methods for the detection of quantum phenomena, such as entanglement and non-locality, in many-body states; (v) first methods to bound causality in Bayesian networks in the presence of quantum information and (vi) experimental proof-of-principle demonstrations of some of these theoretical findings. The successful competition of the research objectives in QITBOX proved the viability and relevance of the device-independent approach, bringing quantum information processing to an unprecedented level of abstraction in which information protocols and primitives are defined without any reference to the internal physical working of the devices. Moreover, the implications of the project went far beyond quantum information processing, as it was demonstrated that the device-independent framework is also useful to solve relevant research problems in other areas, such as condensed matter physics or statistical inference. Therefore, QITBOX not only brought significant advances for our understanding of quantum phenomena and their use for the design of novel quantum information technologies, but also opened new and promising research directions and connections with other fields that deserve further investigation.