Quantum Communications for Security and Quantum Computing
1 INTRODUCTION
There are two predominant approaches to security in the quantum age: Quantum Key Distribution( QKD), which is information theoretic and proven to be unbreakable, and Post- Quantum Cryptography( PQC), which is not information theoretic and may be broken at some point [ 1 ]. A hybrid approach of QKD and PQC is a powerful defense-in-depth combination, removing the single point of failure that exists when only one approach to security is deployed [ 2 ].
This article addresses how this combination can also apply to the subject of quantum communications, bundling QKD and photon entanglement swapping to add quantum memory and quantum repeaters to build a fully defensive strategy. This level of quantum communications could also be the answer to distributed quantum computers [ 3 ], which would enable the goal of realizing cryptographically relevant quantum computers( CRQC) by 2030.
2 ESTABLISHING QKD AS A CORNERSTONE OF A QUANTUM DEFENSE
Before we begin any discussion of quantum security, the efficacy of QKD deserves a review. The National Institutes of Standards and Technology( NIST), charged with developing the new cryptographic algorithms, and other standards organizations such as the National Cyber Security Centre in the United Kingdom [ 4 ] has taken an“ all or nothing” approach to encryption: it’ s PQC or the highway [ 5 ]. It is important to note that these objections were first raised 10 years ago, based on the technology and information available then. However, left unaddressed, the nowantiquated view threatens the credibility of QKD needlessly and unexplainedly. There is compelling evidence that rebuts the five factors cited [ 6 ] [ 7 ] as the reason why NSA and NIST is limiting cryptographic defense to only the PQC algorithms( which were only approved in 2024) [ 8 ].
1. QKD is only a partial solution. This is based on NSA’ s assertion that QKD keys cannot be authenticated from their source, but this is not the case. QKD systems secure communication because it is authenticated at both ends of the exchange.
2. QKD requires special, purpose-built equipment. Yes, QKD requires electro-optic hardware and fiber-optic cables to transmit information. But given the more than 2.5 billion miles of cable around the world, the infrastructure already exists [ 9 ].
3. QKD increases infrastructure costs and opens the door to insider threats. While there are costs associated with the physical deployment of QKD at end points, the evolution of quantum technology and key management systems is happening so rapidly that it will reduce costs and require fewer QKD receptors.
4. 4QKD lacks practical application. This claim is ostensibly based on early trials in QKD development from its origins in 1984. A lot has happened since then.
Journal of Innovation 123