Upper bounds for the security of differential-phase-shift quantum key distribution with weak coherent states
Abstract
In this paper we present limitations imposed by sequential attacks on the maximal distance achievable by a differential-phase-shift (DPS) quantum key distribution (QKD) protocol with weak coherent pulses. Specifically, we compare the performance of two possible sequential attacks against DPS QKD where Eve realizes, respectively, optimal unambiguous state discrimination of Alice's signal states, and optimal unambiguous discrimination of the relative phases between consecutive signal states. We show that the second eavesdropping strategy provides tighter upper bounds for the security of a DPS QKD scheme than the former one.
- Publication:
-
Quantum Communication, Measurement and Computing (QCMC): Ninth International Conference on Qcmc
- Pub Date:
- April 2009
- DOI:
- 10.1063/1.3131346
- Bibcode:
- 2009AIPC.1110..351C
- Keywords:
-
- 03.67.Dd;
- 03.67.Hk;
- 42.50.-p;
- Quantum cryptography;
- Quantum communication;
- Quantum optics