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Hier finden Sie wissenschaftliche Publikationen aus den FraunhoferInstituten. Numerical assessment and optimization of discretevariable timefrequency quantum key distribution
 Physical review. A 95 (2017), No.5, Art. 052312 ISSN: 24699926 ISSN: 24699934 

 English 
 Journal Article 
 Fraunhofer HHI () 
Abstract
The discretevariables (DV) timefrequency (TF) quantum key distribution (QKD) protocol is a BB84like protocol, which utilizes time and frequency as complementary bases. As orthogonal modulations, pulse position modulation (PPM) and frequency shift keying (FSK) are capable of transmitting several bits per symbol, i.e., per photon. However, unlike traditional binary polarization shift keying, PPM and FSK do not allow perfectly complementary bases. So information is not completely deleted when the wrongbasis filters are applied. Since a general security proof does not yet exist, we numerically assess DVTFQKD. We show that the secret key rate increases with a higher number of symbols per basis. Further we identify the optimal pulse relations in the two bases in terms of key rate and resistance against eavesdropping attacks.