Quantum and semi--quantum key distribution in networks

TL;DR

This paper introduces protocols for quantum and semi-quantum key distribution in layered networks using multidimensional separable states, demonstrating their robustness and potential for practical implementation with current technology.

Contribution

It presents new protocols leveraging MSS for secure key distribution in layered networks and provides a method to generalize these protocols for arbitrary network configurations.

Findings

Protocols are robust against eavesdropping strategies.

Resource states can be identified for arbitrary networks.

Key rates depend on local state dimensionalities.

Abstract

In this paper, we utilize the potential offered by multidimensional separable states (MSS) for secure and simultaneous distributions of keys in a layered network. We present protocols for both quantum and semi-quantum key distribution and discuss their robustness against various eavesdropping strategies. We provide a procedure to identify the requisite resource states to generalise these protocols for arbitrary layered networks. Finally, we study the interrelation between the local dimensionalities of states and achievable key rates in a given layer. These proposals are realisable with current technology, thanks to employment of MSS and many advances in generation, manipulation and measurement of higher-dimensional orbital angular momentum states of light.