Quantum distribution of cryptographic keys DQC

This article is a summary of the state of the art of QCD (Quantum Safe Cryptography) as seen through the lens of standardization, and in particular that of ETSI (European Telecommunications Standards Institute). It presents updated and expanded information on standardized QCD, followed by the introduction of QSC (Quantum Safe Cryptography), thus completing the [NM 2 400] article published in 2008 on quantum distribution.

ETSI is an official standards organization in the telecommunications sector, best known for its GSM standards (4G/5G today). With 770 members in 62 countries, it also brings together the major DQC players in the ISG QKD (Industry specification Group, Quantum Key Distribution), ensuring international collaboration between experts.

The most critical secure exchange on public networks (Internet, physical mail) is that which enables symmetrical encryption keys to be set up between Alice and Bob. This step is essential before data can be exchanged. On today's Internet, cryptography is a tough competition between those responsible for the security of information systems (governmental, military, industrial, financial, medical) and hackers, who can be enemies, competitors, investigators, hackers with evil intentions, or sometimes just people who like to take on challenges and share their results on the Internet.

The challenge is therefore to secure data communications globally, as well as the information stored (and encrypted) in our databases. Our information systems sometimes contain secrets that need to be protected for decades. Some data need long-term security. Indeed, thanks to the gigantic storage capacities available at low cost, encrypted data communications considered secure today (especially the most sensitive) can be kept by hackers to be decrypted at a later date. They can in fact wait until design flaws or malfunctions are discovered. The risk of decryption becomes ever greater with time, and especially with the increase in computing power, mathematical discoveries, algorithmic improvements and innovations, and the gradual emergence of quantum computers.

The computing power of networked computers (grids for calculations, services and data, Cloud) is constantly increasing. As a result, the (sometimes fallible) decryption algorithms used are becoming less and less resistant to cryptanalysis, and even less so as a result of certain (unpredictable) mathematical discoveries,...