Orthogonality broadcasting and quantum position verification

New Journal of Physics (2025)

 

In this paper, researchers look at orthogonality — the fact that certain quantum states are perfectly distinguishable — and how it relates to the security of quantum communication.

The team introduces a concept called “orthogonality broadcasting” and asks when it’s possible to copy the distinctiveness (orthogonality) of quantum states and share it with others. They find that in sufficiently complex systems, quantum communication can preserve this distinctiveness when classical communication cannot. They also find when quantum communication cannot preserve this distinctness, thereby improving the security of a protocol called quantum position verification. These findings deepen our understanding of how quantum mechanics can be used to establish a secure network infrastructure.

The paper authors are Ian George (National University of Singapore), Rene Allerstorfer (QuSoft), Philip Verduyn Lunel (Sorbonne Université) and Eric Chitambar (University of Illinois Urbana-Champaign).