In a typical configuration, where the QKD system connects sites, each of the devices (servers, computers, etc.) that perform encrypted communication has to obtain a cryptographic key from the QKD system. However, this proof-of-concept setup conceals the QKD system within the VPN, enabling devices connected to routers to use QKD for encrypted communications without directly detecting the system. In addition, using keys generated through QKD as symmetric keys for the Advanced Encryption Standard (AES) used in iPsec achieved high-speed encrypted communications.
This field experiment was conducted using the QKD-compatible VPN router, FortiGate.
“We are delighted that SoftBank and Toshiba Digital Solutions, have achieved success using our FortiGate in their QKD communication proof-of-concept experiment,” said Kazunori Yozawa, Japan Country Manager, Fortinet Japan G.K. “As the rise of quantum computing increases the risks of using public-key cryptography like RSA, we recognize QKD as a technology in which we, as a cybersecurity company, should take an active interest. We believe the Beyond 5G/6G era will give rise to new smart infrastructure and means of production that will need protection against cyberattack, so we at Fortinet stand behind and together with SoftBank and Toshiba Digital Solutions as they work to bring QKD to market and cyberattack-proof the society of tomorrow.”
SoftBank and Toshiba Digital Solutions aim to further improve and develop quantum cryptographic technologies based on the insights gained from this successful proof-of-concept experiment.
・Compromise of RSA2048
Many of today's communication networks rely on cryptographic techniques such as public-key cryptography (such as RSA and elliptic curve cryptography) and symmetric-key cryptography (such as AES and DES) to ensure high levels of security and confidentiality for communication. However, cryptographic technologies undergo generational changes approximately every 10 years, and it is predicted that by the end of 2030, some of the currently used cryptographic technologies, including RSA2048, will reach the end of their security lifespan.
In addition, the development of quantum computers, which is progressing worldwide, poses a potential threat to public-key cryptography. Quantum computers have the capability to break commonly used public-key cryptosystems, such as RSA and elliptic curve cryptography, jeopardizing the confidentiality of communication. The development of post-quantum cryptographic technologies, such as Post Quantum Cryptography (PQC), is crucial to ensure secure communication in the face of these emerging threats.
QKD is a technology for generating shared cryptographic keys by applying the principles of quantum mechanics. Light, when its intensity is weakened, exhibits not only wave-like properties but also "particle-like" behavior. These particles of light are called "photons." According to the "uncertainty principle" *1 and the "no-cloning theorem," *2 it is impossible to duplicate photons no matter how the technology progress.
Utilizing this principle, the information for generating shared cryptographic keys is transmitted on these photons to the intended recipient during communication, eavesdropping along the communication path must be detected *3. The shared cryptographic keys generated based on this protocol are guaranteed to be secure, as they have not been intercepted by anyone.