Within the sector of quantum computing, quantum
communication systems are a rapidly growing field. In this article,
we look at the development of such systems and some of the related
patents filed in this area.
Quantum communication
Quantum computing technologies will continue to develop and
improve in 2024. One of the main aims of the field has been to
improve the accuracy of quantum computation so that calculations
are performed with fewer errors. Another fast-growing area is
quantum communication, used to increase the security of data
encryption across new quantum networks.
To send quantum data over long distances, photons are used as
qubits (quantum bits, analogous to classical bits used in classical
computing). Photons are transmitted over fibre optic cables that
are laid underground, above-ground or under the sea. The advantage
of using photons for quantum communication is that fibre optic
cable networks already exist across the globe and are used, for
example, to receive and transmit data over the internet.
Data encryption
When sending data over the internet, such as in online financial
transactions or when sending an email, data encryption is used to
securely transmit the data without allowing a third party to read
it. To encrypt data sent over the internet, complicated
mathematical algorithms are used. If a third party wanted to access
this secure data, these algorithms would have to be solved by a
computer. Classical computers could take months or even years to
break these algorithms1, ensuring the safety of the
encrypted data. However, quantum computing is capable of solving
these algorithms on much shorter timescales.
The potential threat posed to current data encryption methods by
advancements in quantum computing, is driving developments in
quantum cryptography. Quantum cryptography aims to provide more
secure data encryption protocols against potential quantum hacking
for data transmission across quantum networks.
Patents in the field of quantum cryptography are directed both
toward hardware and software. For example, EP1748595 describes apparatus that enables the
communication of quantum encrypted data, whereas EP3758289 describes both an algorithm that can
withstand quantum attacks as well as suitable hardware for the
implementation of the algorithm.
Data transmission
In quantum communication, data is transmitted using qubits
instead of classical bits. The advantage of transmitting qubits is
that an eavesdropper can be easily detected. This is primarily
because if an eavesdropper attempted to read the quantum data, the
quantum state of the qubit would collapse (a simplified explanation
of this can be found in Part II of this series). Additionally, the
data cannot be copied by a third party. This is due to the
no-cloning theorem of quantum mechanics, which essentially says
that it is impossible to create an identical copy of an unknown
quantum state.
As well as a more secure means of data transfer, quantum
communication also allows a near-instantaneous transmission of
data. Quantum communication networks are therefore being actively
researched and built by various companies and government
institutions. These networks can be built using two forms: (i)
on-the-ground cable communication; and (ii) satellite
communication. The main limitation in either of these communication
forms is the loss of photons with distance. Photons can be lost due
to scattering or absorption, and increasing the distance of travel
also increases the probability of photon loss.
Quantum networks
One of the organisations actively developing quantum
communication networks is the Quantum Corridor TM. This
organisation is developing one of the fastest fiber-optic quantum
networks in North America, stretching between Indiana and Chicago.
Their aim is to provide businesses, research centres and government
facilities with the ability to transmit data at nearly
instantaneous speeds. In November 2023, data sent over the current
19 km network was sent with a delay of only 0.266
milliseconds2. Companies such as Toshiba Systems, that
have already developed methods for transmitting encrypted quantum
data over fiber-optic cables (e.g. EP3220574), are also using this network to
apply their technologies3.
Another quantum communication network is being developed between
England and Ireland4, using the recently built subsea
fibre optic network Rockabill5 that stretches over 224
km. Experiments in 2023 conducted by researchers from the
University of York in collaboration with the Quantum Communications
Hub and euNetworks Group Limited (who funded the construction of
Rockabill), showed that single and entangled photons can
successfully be sent from one end of the network to the other.
Transmitting an entangled photon, means that changing the state of
the other photon in the entangled state instantaneously changes the
state of the transmitted photon.
Beyond fibre optic networks, satellite networks for quantum
communication are also being developed. One example is China’s
Micius satellite launched in 2016, which is being used to send
quantum data over a distance of 3,800 km between Russia and
China6,7. Several patents directed toward
satellite-to-ground quantum communication have been filed in China
including by the State Grid Corporation of China, such as CN112564900 for transmitting quantum encrypted
data using quantum channels between a satellite and a ground
station.
An industry that will be heavily targeted by quantum hacking
attacks is the finance sector and its technologies (Fintech). As
such, more secure data encryption for Fintech is being actively
developed in preparation for a post-quantum world. Our article
‘Top five patents for Fintech inventions’,
explores various patented Fintech technologies including
quantum-proof contactless payments.
What developments can we expect in quantum communication?
Optimizing quantum data transmission will likely require hybrid
networks that will include both satellites and fibre optic cables.
As these networks grow, we will likely see the emergence of a
quantum internet8. The first shopping transactions over
a quantum computing network – or a small quantum internet
– have already been carried out in China9. To
expand such small networks into hybrid global ones, researchers are
looking to optimize the number of satellites needed and the ideal
height at which these satellites should be placed. In addition to
advancements in quantum computing, the technological developments
involve simulations of satellites and materials research to improve
the composition of fibre optic cables in order to reduce photon
loss.
Quantum communication remains an active area of technological
development across multiple sectors. As quantum computers evolve,
the competition for building wider and more secure quantum networks
continues.
This is the third article in our series on Patenting Quantum
Computing in Europe. Our first and second articles are available here.
Footnotes
1. Quantum Xchange. https://quantumxc.com/blog/quantum-cryptography-explained
2. The Quantum Insider. https://thequantuminsider.com/2023/11/09/quantum-corridor-launches-super-fast-super-secure-fiber-optic-network/
3. Quantum Corridor. https://www.quantumcorridor.io
4. euNetworks. https://eunetworks.com/network/network-developments/quantum-communication-research-success-on-rockabill
5. euNetworks. https://eunetworks.com/news/eunetworks-delivers-new-critical-fibre-infrastructure-in-the-uk-and-ireland
6. Liao, SK., Cai, WQ., Liu, WY. et al.
Satellite-to-ground quantum key distribution. Nature
549, 43 (2017). https://doi.org/10.1038/nature23655
7. South China Morning Post. https://www.scmp.com/news/china/science/article/3246752/china-and-russia-test-hack-proof-quantum-communication-link-brics-countries
8. Khatri, S., Brady, A.J., Desporte, R.A. et al. Spooky
action at a global distance: analysis of space-based entanglement
distribution for the quantum internet. npj Quantum
Information 7, 4 (2021). https://doi.org/10.1038/s41534-020-00327-5
9. New Scientist. https://www.newscientist.com/article/2411985-first-unhackable-shopping-transactions-carried-out-on-quantum-internet
The content of this article is intended to provide a general
guide to the subject matter. Specialist advice should be sought
about your specific circumstances.
#Quantum #Computing #Part #III #Fin #Tech
