Quantum Clock Synchronization with a Single Qudit

TL;DR

This paper introduces a quantum algorithm that achieves clock synchronization in multiprocess networks with many faulty processes using only a single quantum system, improving reliability over classical methods.

Contribution

It presents a novel nonrecursive quantum algorithm for Byzantine agreement and clock synchronization that works with arbitrary many faulty processes using just one qudit.

Findings

Successfully synchronizes clocks despite many faulty processes

Uses only a single quantum system, reducing complexity

Outperforms classical recursive algorithms in fault tolerance

Abstract

Clock synchronization for nonfaulty processes in multiprocess networks is indispensable for a variety of technologies. A reliable system must be able to resynchronize the nonfaulty processes upon some components failing causing the distribution of incorrect or conflicting information in the network. The task of synchronizing such networks is related to detectable Byzantine agreement (DBA), which can classically be solved using recursive algorithms if and only if less than one-third of the processes are faulty. Here we introduce a nonrecursive quantum algorithm that solves the DBA and achieves clock synchronization in the presence of arbitrary many faulty processes by using only a single quantum system.