Speaking on Marine Technology TV this week, Dr Tim Gallaudet, Rear Admiral, U.S. Navy (ret) and CEO of Ocean STL Consulting, highlighted quantum communications as an important development in subsea technology. It may not happen in 2025 as the technology is still in its infancy, but it could be mainstream in the next decade, Gallaudet says.
Today, sensitive data is typically encrypted and then sent across fiber optic cables together with digital “keys” that are needed to encrypt and decrypt the information. However, hackers can access the data (the string of 0 and 1 bits used by traditional computers) without leaving a trace.
In contrast, quantum communication takes advantage of the laws of quantum physics to protect data. If a hacker tries to observe the data in transit, the quantum state of the photons collapses so there is evidence that a breach has occurred.
An advance in the technology was announced this week when the German Aerospace Center and Ulm University demonstrated how quantum data can be securely transmitted on fiber optic cables while they attempted a cyber attack on the data. The researchers, working on the development of a quantum internet, achieved the tap-proof transmission of data using Quantum Key Distribution.
It works like this: The sender transmits the encrypted data as a conventional binary code over a standard data network to the receiver. The sender and receiver jointly generate the quantum key for encryption and decryption that is transferred into the quantum physical states of individual photons. This process is carried out separately and securely via a quantum channel. Eavesdropping incursions are immediately detected if the data rate suddenly drops, at which point the system stops generating the key.
Another technology development came with research conducted at Northwestern University in Illinois. The researchers demonstrated quantum “teleportation” over a fiber optic cable already carrying traditional Internet traffic. This introduces the possibility of combining quantum communication with existing Internet cables – greatly simplifying the infrastructure required for distributed quantum computing applications.
Only limited by the speed of light, quantum teleportation enables a new, ultra-fast and secure way to share information between distant network users, where direct transmission is not necessary. The process works by harnessing quantum entanglement, a technique in which two particles are linked, regardless of the distance between them. Instead of particles physically traveling to deliver information, entangled particles exchange information over great distances — without physically carrying it.
With classical communications and quantum communications coexisting in the same fiber optic network, the importance of subsea cable security will remain a key issue. It’s a topic that Gallaudet emphasized on Marine Technology TV, citing recent cases of damaged cables in the Baltic and Taiwan. “They transmit 99% of the information that our economy and national defense depends on.”
He also discussed advances in domain awareness for protecting such critical infrastructure: “Seabed warfare: it’s still a thing, and it’s bigger than it ever has been.”