Research carried out in China has experimentally verified that the extreme sensitivity of a quantum cryptography network can detect earthquakes and landslides, however slight they may be, with an accuracy of around 1 kilometer, a great promise to prevent seismic catastrophes.
A quantum communication technique can measure minute vibrations in the ground, making it potentially useful for detecting earthquakes and landslides, no matter how small, according to new research.
Although there are 500,000 earthquakes around the world each year, most are too weak to feel, even though they can be precursors to larger tremors. They simply go unnoticed.
The technology that can increase the ability to predict possible earthquakes or landslides, according to the new research, is called quantum crypto networkwhich offers the most secure and insurmountable telecommunications achieved to date.
All secure communications are currently based on the use of cryptography, whereby the information is encrypted using a key that allows only the participants who know it to be able to decrypt the messages exchanged between them.
The danger of quantum computers
Cryptography techniques are based on mathematical problems that are complex to solve. As computing capacity grows, the resolution time for these problems, and therefore the security of the keys, decreases.
The size of the keys and the complexity of the encryption algorithms have had to increase as the computing capacity has grown.
And these techniques can become completely obsolete with the appearance of quantum computerscapable of applying the principles of Quantum Mechanics to solve currently insoluble problems, including breaking the keys generated by current cryptography methods.
Quantum technologies offer, however, a solution to the vulnerability of current methods, which can also be exploited to predict earthquakes and seismic movements.
Quantum key distribution
With these technologies it is possible to apply quantum principles to exchange a key between the ends of a communication channel, so that this key is safe against any attack, including that of a quantum computer. Quantum technology even makes it possible for any attempted attack to be immediately detected.
Quantum Key Distribution (QKD) is one of these technologies: it not only solves the problem of the threat that quantum computing poses to the cryptographic algorithms in use, but it can also provide a much higher level of security to any key exchange. data.
New research, led by Jian Wei Panfrom the University of Science and Technology of China (USTC), has used a type of QKD called Dual Field QKD (TF-QKD)which uses the way individual photons interfere with each other to encrypt data: it successfully sends encrypted data over a wire with minimal loss of information.
Pen’s experiment was carried out in the laboratory and demonstrated for the first time that the system TF-QKD for quantum key distribution works like a charm: Sent encrypted data over 658 kilometers, one of the longest distances covered by this technology to date.
The most relevant aspect of this result is that the application of TF-QKD not only managed to reduce the number of nodes necessary to convey information between sender and receiver, but also demonstrated at the same time that the extreme sensitivity of this quantum cryptography system can be used to detect changes in the environment, such as possible seismic movements.
The system was not only able to detect deliberately small changes in the network, but also to locate where each vibration occurred, with an accuracy of around a kilometer.
Although this technology shows promise for seismic detection, the researchers note that it still needs to be improved so that the TF-QKD system can be integrated into a large-scale quantum cryptography network, which is when it would be really useful to geologists.
In this regard, it must be taken into account that China is not only one of the countries most affected by earthquakes, but also leads the development of quantum cryptography networks throughout the world. It is not unreasonable to think that China will probably also be a pioneer in detecting earthquakes through its quantum cryptography networks.
Quantum Key Distribution over 658 km Fiber with Distributed Vibration Sensing. Jiu-Peng Chen et al. Phys. Rev. Lett. 128, 180502; 2 May 2022. DOI:https://doi.org/10.1103/PhysRevLett.128.180502