Quantum Key Distribution QKD (DQC)

This article is the updated 2023 version of article H 5 214 entitled "Quantum Key Distribution QKD (DQC)", written in 2015, which in turn updated the 2008 article [NM 2 400] on quantum cryptography. For more on "classical" cryptography (RSA, AES, DES), interested readers can refer to the article [H 5 210] . A glossary in paragraph 7 provides definitions of the terms and expressions most frequently used in the article. All acronyms used are detailed in paragraph 8 .

This article introduces Quantum Key Distribution (QKD) as seen through the lens of QKD and QSC (Quantum Safe Cryptography) standardization led by the ETSI (European Telecommunications Standards Institute), which has 910 members in 60 countries and is developing the world's mobile telephony standards (GSM, 4G, 5G).

Cryptography is a competition between those responsible for the security of critical information systems (governmental, military, industrial, financial, medical) and hackers, who can be enemies, competitors, investigators, computer experts with malicious intentions, or sometimes just people who like to take on challenges and share their results on the Internet.

The challenge is to secure data communications and information stored (encrypted) in databases. This critical information needs long-term security. Indeed, thanks to the gigantic storage capacities available at low cost, encrypted data communications considered secure today can be stored and decrypted at a later date. The risk of decryption increases...