Quantum Key Distribution (QKD) and security

In the collective imagination, quantum computing has been relegated to science fiction for many years, but thanks to recent developments in technologies and substantial investments by major players, we are beginning to see progress in this area.

In the increasingly hybrid reality in which we live, with interactions both in presence and remotely, quantum computing, among other things, will play an increasingly important role in issues related to the security of data and information exchanged.

At the same time, the need for companies to address the implications of quantum computing developments to get ready for a post-quantum future is becoming more and more urgent.

Today all organizations (both public and private) have the urgency to prepare to face this revolution and learn how to protect their most precious assets.


Classical computer and the advent of quantum computer

Today’s society has now adapted, even going so far as to shape itself, according to Information Technologies.

Whether it is prediction / statistical models, computational calculation skills, banal entertainment or work tools, the so-called “classic” computers are now in common use and indispensable for our livelihood.

In the most recent period, however, a “new” technology is shaking the world of cybersecurity: the quantum computer.

In extremely simple words, a quantum computer represents the evolution of the traditional computer.

The common terminals that we all have at home or in the office process information by reasoning in the logic of binary code, that is a mathematical system composed of a defined series of 0’s and 1’s which, taken as a whole, form a “bit” of information, therefore a data in digital form.

But not the quantum computer. In fact, it departs from binary logic to assume a computational reasoning based on the laws of quantum mechanics.

If in the binary code the 0 and 1 are two mutually exclusive states (ie “0 = off” and “1 = on”), in the logic of quantum computers these states can coexist at the same time: in this case, the classic “bit” of classical computers becomes a “qubit” (quantum-bit) in quantum computers.

This difference allows the new quantum computers to have a computational capacity immensely superior to that known to date.

This capacitive leap, however, in addition to creating new opportunities (still largely unexplored) in the most disparate application areas, creates at the same time a serious alarm for everything that concerns the tightness of security for classic IT systems, or those that we all use.

In fact, most of today’s computer security systems are based on classical cryptographic logic, or on the assumption of an objective computational difficulty in encrypting and decrypting the information exchanged.

The great capabilities exhibited by quantum computers are potentially able to break this computational “hardness” with discrete ease, forcing everyone to run for cover and develop effective response solutions.

To do this, there are currently two main approaches:

The first approach is Quantum Key Distribution (QKD): a technology based on quantum mechanics that provides unconditional security, i.e. independent of the computation model considered.

The second approach is Post-Quantum Cryptography (PQC): design of classical cryptographic schemes whose security is based on problems considered resistant even to quantum computers.

You can find more information on these two issues in a dedicated article on our blog. Here, we will deal with describing Quantum Key Distribution.


What is Quantum Key Distribution

Today one of the biggest vulnerabilities in cryptographic security lies in the exchange of encryption keys.

These keys represent the cryptographic codes necessary to validate the security and non-compromise of the data and information exchanged by the communicating, issuing and receiving parties.

Quantum Key Distribution (QKD) is a physical layer method that allows unconditionally secure distribution of random keys between remote users.

In short, QKD is a technology that exploits the physical properties of photons to distribute secret keys between the ciphers used to guarantee the security of the communication in progress.

Given the extreme sensitivity of photons, the slightest disturbance in the communication channel (due, for example, to a hostile actor who intrudes on the communication to exfiltrate sensitive or confidential information) causes the system to reject the compromised key, interrupting the communication itself and making any theft of data or information impossible.


QKD and security: Telsy’s answer

Recently, Telsy join the share capital of QTI srl, an Italian leading company in the QKD field, which allowed the development of an end-to-end encryption system compatible with the current telecommunications infrastructure for civil and military applications, based on the integration between QTI’s QKD system and Telsy’s classical cryptography solutions.

Quell-X is the solution proposed by QTI and Telsy, a QKD system consisting of an Alice unit and a Bob unit capable of generating quantum keys for ultra-secure communications.

The security of the keys is guaranteed by the laws of quantum mechanics, which make it possible to identify any eavesdropper in the communication channel.

The great versatility of Quell-X allows its implementation on any network configuration: point-to-point links, trusted note configuration, more advanced network types (i.e., ring or star networks).

The solution is optimized for full integration with Telsy ciphers.



Here are some of the practical applications and uses of Quantum Key Distribution:

  • Cryptographic key distribution infrastructures
  • Data center security
  • Protection of medical data
  • National and transnational backbones
  • Long distance key distribution based on trusted nodes
  • Distribution of keys on reconfigurable networks (star, ring, software defined networks)
  • Governmental and financial data security
  • Safety of critical infrastructures: airports, ports, gas-distribution and power-grids distribution

Learn more about our Quantum solutions.