The Keys to Quantum Secrets

Abudhahir Buhari

We propose a multi-party quantum key distribution protocol which enables all the receivers can convert their respective private shared key into common secret key without use of entanglement.The main component of our protocol is a simple post quantum scheme for achieving the higher secret key rate.Efficiency of the extracted key rate is almost 100%.We assume that sender established the pre-shared private secret keys and a common secret number with the receivers.Our proposed scheme sends n strings of number to n receivers in the public channel to convert their respective shared secret key into common secret key in the presence of Eve.We also analyze the complexity of attack by the adversary to guess the secret key.

Igor M. Arbekov, S. N. Molotkov

Abstract Basic configuration in quantum cryptography is a point-to-point quantum key distribution. In networks with quantum key distribution, the keys received on different network segments are different. For information encryption between arbitrary network nodes it is necessary to have agreement of the keys distributed in different segments of network through a public classical communication channel. The secrecy criterion for keys independently distributed in different network segments is formulated in terms of the trace distance. These are the so-called ε –secret keys. The paper deals with the issue of the secrecy of the agreed keys. We propose the method of secret keys agreement in which the agreement of two ε 1 , ε 2 –secret keys distributed in different segments leads to a common ( ε 1 + ε 2 ) –secret key. It is shown that in order to agreed common key will be ε –secret, it is sufficient that the keys on the individual segments are ε /2–secret.

Wolfgang Smith

Neil J. Savage

Fengyou Sun, Yuming Jiang

This paper aims to present a mathematical tool useful for quantum key distribution network configuration. In particular, the paper studies the throughput of secret key distribution in a quantum key distribution network with trusted repeaters. In addition, the backlog of secret keys at a trusted repeater is also investigated. The analysis is based on the queueing principle of secret keys in the trusted repeater, implied by that the transmission of secret keys in the network is store-and-forward. The obtained results are applied to a discrete-variable protocol with weak coherent pulse sources, where realistic system parameters are integrated in the analysis. It is shown that, if the secret key rates on the transmission path are different, the transient throughput of secret key distribution through the network also vary, located between an upper bound and a lower bound of the secrete key distribution rate.