• Blog
  • The Closeting of Secrets – Physics and Cryptography - Professor Adrian Kent

The definition and properties of information may seem to be fundamental features of the world that are independent of how particles, fields and space-time behave. In fact, though, information is fundamentally physical and twentieth century physics has radically changed our understanding of its nature and properties. Einstein’s relativity theories tell us that information cannot travel faster than the speed of light in vacuum. Quantum theory tells us that the information carried by microscopic systems is qualitatively different from the familiar ``classical’’ information with which we presently communicate and compute: for example, quantum information cannot be copied. These realisations have led to new applications and emerging new technologies, including relativistic quantum cryptography and new forms of quantum communication and computation in space-time. This lecture will illustrate several ways in which physics-based cryptography and communication allow otherwise unachievable forms of security and flexibility, including guaranteeing a fair coin toss for mistrustful parties, making and later revealing secret predictions that carry a guaranteed time stamp, and secure forms of money that emulate quantum particles by following multiple paths and recombining to solve otherwise insoluble trading problems. We will also ask how confident we should be that we now fully understand how information is carried and processed in nature, and whether new physics discoveries might yet change our understanding and lead to further technological advances.

Adrian Kent is Professor of Quantum Physics at the Department of Applied Mathematics and Theoretical Physics, University of Cambridge, a Fellow of Wolfson College and Director of Studies in Mathematics at Darwin College. He is also a Distinguished Visiting Research Chair at Perimeter Institute for Theoretical Physics, Fellow of the UK Institute of Physics, Founder Member of the Foundational Questions Institute and Charter Honorary Fellow of the John Bell Institute for the Foundations of Physics. Adrian’s research interests include the nature of physical reality, fundamental tests of quantum theory and its relationship to gravity, the properties of quantum information in space-time, and applications of fundamental physics to new forms of quantum and relativistic cryptography, communication and computation.

Keywords: IPW Intelligence Physical World FFFM IPW 2019, Kent

quantum information cannot be copied

Of course not, precisely because it does not even exist, in the real, physical world; it only exists in the imagination of physicists, that have completely failed to comprehend Shannon's astonishing discovery, regarding what information must necessarily be.

    Robert McEachern Hi , why do you consider that the informations don t exist, it seems that we need informations to understand the universal mechanisms, we cannot affirm this kind of conclusion , an information is not an invention in the minds of physicists, now of course there are differences with what is an information created by this universe and the informations that we have invenced for the computing with the bits, But without information we could not have the diversity of mendeleev table for the atoms and this evolution with the chemistry and biology and cosmology

      Steve Dufourny
      Steve,
      Please read the link I provided: "Quantum Information" and "Information", are two entirely different types of beasts. The first is only a Unicorn - a creature that exists only in myths (as told by physicists). The second is an actual, real horse, first discovered to actually exist in nature, by Claude Shannon, 75 years ago. The latter has surprisingly little to do with either your, or anyone else's (particularly physicists), common conceptions associated with the word "Information." In common parlance, the words "information" and "data" are widely regarded as being more-or-less synonymous. But they are very different concepts, in Shannon's theory.

        Robert McEachern ok I see clearer what you meant , I tell me that we need also quantum informations to have this evolution and all the diversity of this universe in fact , now what are these informations , I believe that maybe the DE is informational and antigravitational and imply a fifth force and encodes the photons and the CDM to create this ordinary baryonic matter , the universe has not only vcreated these photons and this GR for me , if the DE and DM exist there are reasons and we have probably deeper scalar fields massless and massive for our QM,

        Write a Reply...