Disruptive Concepts and Technologies: Quantum Technology
By Kelly McSweeney
Until recently, the more exotic effects of quantum physics were limited to academic experiments. Now, the second wave of quantum technology is on the way.
“People are diving deeper and looking to exploit the really strange things at the roots of quantum physics,” says Dr. Ryan Aguinaldo, portfolio manager for emerging technologies.
Dr. Aguinaldo leads a team within Northrop Grumman’s Disruptive Concepts and Technologies (DC&T) organization that’s investigating how quantum technology can provide capabilities not found in classical physics.
Communications for Quantum 2.0
DC&T scientists and engineers are exploring ways to harness the laws of quantum physics to improve critical information technologies such communications, computing and sensing. Incorporating quantum effects in these technologies provides the potential for superior performance relative to their classical (or “non-quantum”) counterparts, for certain applications.
As these quantum-enabled technologies progress, it will be vital to develop ways to share quantum information across varying length scales, ranging from the inside of a computer chip to global distances. The best ways to accomplish this are still unclear, but breakthroughs could have far-reaching impacts for the ultimate feasibility and performance of quantum systems.
Eavesdropping and Quantum Mechanics: Quantum Key Distribution
One application of quantum communications is Quantum Key Distribution (QKD), which helps guarantee the security of a communications network by virtue of the laws of physics. Most of today’s Internet relies on the assumed difficulty of certain mathematical problems – an assumption that breaks-down in the era of quantum computers. But QKD aims to provide guaranteed security against future advances in computer power, to include that of a quantum computer.
“There’s a principle in quantum mechanics that you can’t clone arbitrary quantum states,” says Dr. Aguinaldo. This simple principle is at the heart of how QKD works.
A classical bit is only either a 0 or a 1, while a quantum bit (qubit) can be in a superposition; in other words, a 0 and 1 at the same time. The phenomenon of “measurement collapse” means that when you measure a qubit, it always collapses back into either a 0 or 1 (a classical state), destroying the quantum information it used to hold. Similarly, qubits can’t be copied without altering the state, a principle known as the No Cloning Theorem.
Symmetric cryptography, used for everyday communications, encrypts a message to an unrecognizable form using a key. This method usually keeps information safe, but getting the key to the right place remains vulnerable. QKD uses the No Cloning Theorem to ensure that information sent over a network has not been intercepted or copied by a third party.
“QKD enables you to distribute keys with confidentiality of the key distribution channel guaranteed by the laws of physics,” says Dr. Aguinaldo.
Making QKD Practical
The academic community has focused on fundamental investigations of QKD, with relatively little effort focused on architecting the solutions needed to make it practical. This is where DC&T comes into action, explains Dr. Aguinaldo. The team is bringing scientists, mathematicians and engineers together to integrate QKD into a practical network architecture.
“What we’re doing is bridging the physics and engineering worlds to re-look at QKD from a network architecture perspective,” says Dr. Aguinaldo.