Quantum communication: an Italian public demonstration

May, 2021

The security of communications is a pivotal aspect to ensure the authenticity, integrity and confidentiality of the information that is exchanged daily across the Web. In today's world, that functions thanks to the exchange of information via the Internet, the security of communications is one of the main priorities for the public as well as for the private sector and for individual citizens.
Different security methods are used depending on the required level of security. The safest method uses two copies of an identical cryptographic key — basically a random sequence of numbers — that are owned by both the sender and the recipient of the message, and can be used only once. However, there is a problem: How can sender and recipient share the same key without creating a security risk? Traditionally the best option is to trust the human or electronic courier in charge of transmitting the key.
Quantum technologies can solve this problem. Whereas normally it is possible to intercept the key and copy it while the sender and the recipient remain unaware of the security breach, this is not possible if they are using quantum keys. Any attempt to make a copy of a quantum key causes the key to change, which can be easily noticed by the recipient by simply comparing parts of the two copies.
In the field of quantum communications, Italy is at the forefront and several Italian research groups have already achieved very important results.
During the closing ceremony of ESOF2020 (EuroScience Open Forum), held in Trieste on September 6th 2020, the Quantum Communications group of the National Institute of Optics of the National Research Council (CNR-INO) along with the University of Trieste and the Technical University of Denmark (DTU) have publicly presented an encrypted videoconferencing system with QKD.
The quantum exchanged cryptographic key was used for a secure communication between the Rector of the University of Trieste Roberto di Lenarda, connected by the Department of Information Systems, and the then Prime Minister Giuseppe Conte, who was on the stage of the ESOF2020 Auditorium at the Porto Vecchio in Trieste.
A video-trailer, summing up the highlights of this demonstration of quantum communication, was realized by the organizers and can be viewed here.