Progress made in secure quantum communications

Junsen Lai, Wenyu Zhao, Haiyi Zhang

Gui‐Lu Long

Eleni Diamanti

Bhaskar Kanseri, Sohan Singh Bisht, Abhay Singh Dulta

Recent progress in quantum technologies has brought quantum communication and networking from a largely theoretical idea to an emerging practical reality. By exploiting fundamental quantum phenomena such as superposition and entanglement, quantum communication promises capabilities that are fundamentally different and out of reach for classical communication systems, particularly in terms of security and information sharing. This review aims to present the essential theoretical concepts required to understand quantum communication, alongside an experimental and engineering perspective that highlights how these ideas are realized using real hardware. We explain core principles and protocols in a manner that connects the physics to practical system design, allowing readers to see how quantum theory and communication technology jointly enable quantum networking. The paper further surveys recent experimental and technological advances that have made practical quantum communication possible, emphasizing the role of photonic hardware, sources, detectors, and integrated platforms in enabling key operations, now leading to deployment of multi-node long-distance quantum networks. Finally, we also present the current developments in quantum-secure communication and quantum networking efforts undergoing in India, placing them in the context of the global progress.

Thomas Zasowski

Quantum computers have made huge progress in recent years. In this tutorial paper, we explain why they pose a threat to encryption methods that are used in today’s communication networks. As there is the unique opportunity of 6G becoming the first cellular standard where post-quantum security could be considered from the very beginning, we present approaches to achieve post-quantum secure communications. Benefits and drawbacks of quantum key distribution (QKD) and post-quantum cryptography (PQC) are compared. Suggestions are made on how these approaches can be considered resulting in a post-quantum-safe 6G standard.

I. Lucio-Martinez, Philip K. Chan, Steve Hosier +2 more