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In classical and quantum information theory, operational quantities such as the amount of ran-domness that can be extracted from a given source or the amount of space needed to store given data are normally characterized by one of two entropy measures, called smooth min-entropy and smooth max-entropy, respectively. While both entropies are equal to the von(More)
According to quantum theory, measurements generate random outcomes, in stark contrast with classical mechanics. This raises the question of whether there could exist an extension of the theory that removes this indeterminism, as suspected by Einstein, Podolsky and Rosen. Although this has been shown to be impossible, existing results do not imply that the(More)
Outline • Motivation for device-independence • Brief History • Recent developments • Main result • Remaining problems and open questions Theoretical Start with 'clean', well-defined assumptions and try to prove security based on these. Two sides of cryptography Practical Try to build devices that satisfy the theoretical assumptions as closely as possible.(More)
Alice is a charismatic quantum cryptographer who believes her parties are unmissable; Bob is a 1 glamorous string theorist who believes he is an indispensable guest. To prevent possibly traumatic collisions of self-perception and reality, their social code requires that decisions about invitation or acceptance be made via a cryptographically secure variable(More)
T owards the end of 2011, Pusey, Barrett and Rudolph derived a theorem that aimed to show that the quantum state must be ontic (a state of reality) in a broad class of realist approaches to quantum theory. This result attracted a lot of attention and controversy. The aim of this review article is to review the background to the Pusey–Barrett– Rudolph(More)
We address the question of whether the quantum-mechanical wave function Ψ of a system is uniquely determined by any complete description Λ of the system's physical state. We show that this is the case if the latter satisfies a notion of " free choice ". This notion requires that certain experimental parameters, which according to quantum theory can be(More)