Finite-key analysis on the 1-decoy state QKD protocol

It has been shown that in the asymptotic case of infinite-key length the 2-decoy state QKD protocol outperforms the 1-decoy state protocol. Here, we present a finite-key analysis of the 1-decoy method. Interestingly, we find that for practical block sizes of up to $10^8$ bits, the 1-decoy protocol achieves for almost all experimental settings higher secret key rates than the 2-decoy protocol. Since using only one decoy is also easier to implement, we conclude that it is the best choice for practical QKD.Comment: 6 pages, 7 figures, Pape

Constructing Pointed Hopf Algebras by Ore Extensions

AbstractWe present a general construction producing pointed co-Frobenius Hopf algebras and give some classification results for the examples obtained

Adopting a 'bifocal approach' in Swiss academic mentoring programmes - challenges and opportunities

Mentoring programmes have been accused of inadequately addressing organisations' gendered cultures. In reaction to this, mentoring approaches started applying a dual focus, i. e. targetting both individual development and organisational change. This paper explores - through the lens of the 'bifocal approach' - whether and how two Swiss academic mentoring programmes for female advanced doctoral students and early postdoctoral scholars have adopted a a dual focus. The paper shows that the programmes have developed strategies adopting this approach to a certain extent and discusses the challenges and opportunities experienced. 14.02.2014 | Julia Grünenfelder (Luzern

Performance and security of 5 GHz repetition rate polarization-based Quantum Key Distribution

We present and characterize a source for a 5 GHz clocked polarization-based simplified BB84 protocol. Secret keys are distributed over 151.5 km of standard telecom fiber at a rate of 54.5 kbps. Potentially, an increased clock frequency of the experiment introduces correlations between succeeding pulses. We discuss the impact of these correlations and propose measurements to estimate the relevant parameters.Comment: 5 pages, 3 figures, submitted to Applied Physics Letter

Simple and high-speed polarization-based QKD

We present a simplified BB84 protocol with only three quantum states and one decoy-state level. We implement this scheme using the polarization degree of freedom at telecom wavelength. Only one pulsed laser is used in order to reduce possible side-channel attacks. The repetition rate of 625 MHz and the achieved secret bit rate of 23 bps over 200 km of standard fiber are the actual state of the art