Multi-partite entanglement can speed up quantum key distribution in networks
Michael Epping, Hermann Kampermann, Chiara macchiavello, Dagmar Bruß · New Journal of Physics · 2017
The laws of quantum mechanics allow for the distribution of a secret random key between two parties.Here we analyse the security of a protocol for establishing a common secret key between N parties (i.e. a conference key), using resource states with genuine N-partite entanglement.We compare this protocol to conference key distribution via bipartite entanglement, regarding the required resources, achievable secret key rates and threshold qubit error rates.Furthermore we discuss quantum networks with bottlenecks for which our multipartite entanglement-based protocol can benefit from network coding, while the bipartite protocol cannot.It is shown how this advantage leads to a higher secret key rate. Multipartite QKD: protocol and security analysisThe entanglement-based Ekert protocol [7] can be generalised to N parties as follows, see also [31,34].The parties A and B 1 , B 2 , ..., B N 1 -share an N-partite entangled state and perform local projective measurements.The