Abstract:

Quantum key distribution(QKD)is used in quantum
cryptographic systems to exchange secret key between parties
who need to communicate secretly.According to the structure
of European Secoqc QKD network,a QKD protocol is proposed.
Entanglement swapping between Einstein-Podolsky-Rosen(EPR)
pairs can be used to exchange message bits in two remote places.
Based on this idea,n+1 EPR pairs are used as logical quan-
tum channel(for n nodes per routing),while measurements of
Bell operator are transmitted by classical channel.Random space
quantum channel selection is exploited in our protocol to improve
the probability of revealing Eve.Compared with traditional EPR
protocol,the proposed protocol exhibits many features,which are
minutely described.