Quantum walk-based protocol for secure communication between any two directly connected nodes on a network

TL;DR

This paper introduces a quantum walk-based algorithm to generate entanglement between directly connected nodes in a quantum network, enabling secure and private communication channels across arbitrary network topologies.

Contribution

It presents a novel quantum walk algorithm for entanglement generation between network nodes, facilitating secure quantum communication in arbitrary network topologies.

Findings

High probability of entanglement between source and target nodes

Negligible probability of walker at other nodes after implementation

Effective across various random network models

Abstract

The utilization of quantum entanglement as a cryptographic resource has superseded conventional approaches to secure communication. Security and fidelity of intranetwork communication between quantum devices is the backbone of a quantum network. This work presents an algorithm that generates entanglement between any two directly connected nodes of a quantum network to be used as a resource to enable quantum communication across that pair in the network. The algorithm is based on a directed discrete-time quantum walk and paves the way for private inter-node quantum communication channels in the network. We also present the simulation results of this algorithm on random networks generated from various models. We show that after implementation, the probability of the walker being at all nodes other than the source and target is negligible, and this holds independent of the random graph generation model. This constitutes a viable method for the practical realisation of secure communication over any random network topology.