Security analysis of quantum cryptographic schemes in the presence of side channels
Final Report Abstract
The main contribution of our project was to clarify the connection between quantum correlations and device independent quantum cryptography. We were able to show that the origin of device independent security does not lie in the structure of any specific Bell inequality, but is a general property of extremal quantum correlations. This result implies a new way of thinking about device independent security and has the possible application of finding new methods to certify security in quantum cryptography. In a first subproject, we defined a novel set of quantum cryptography protocols based on retrodiction. We showed, that any quantum retrodiction protocol implies a corresponding cryptography protocol and we showed the security of these protocols in an error-free setting. In a second subproject, we studied general (i.e. infinite dimensional) quantum correlations. We were able to show that the physical question, whether all quantum correlation can be approximated by finite dimensional systems, is equivalent to a fundamental open problem from operator theory, namely Connes’ conjecture.
Publications
- Quantum cryptography as a retrodiction problem. Phys. Rev. Lett., 103:220504 (2009)
A. H. Werner, T. Franz, and R. F. Werner
(See online at https://dx.doi.org/10.1103/PhysRevLett.103.220504) - Connes’ embedding problem and Tsirelson’s problem. J. Math. Phys. 52, 012102 (2011)
M. Junge, M. Navascues, C. Palazuelos, D. Perez-Garcia, V. B. Scholz, R. F. Werner
- Extremal Quantum Correlations and Cryptographic Security. Phys. Rev. Lett., 106:250502 (2011)
T. Franz, F. Furrer, and R. F. Werner
(See online at https://dx.doi.org/10.1103/PhysRevLett.106.250502) - Quantum correlations and quantum key distribution, Dissertation, Leibniz University Hannover (2013)
Torsten Franz
