SK Telecom develops advanced quantum repeater

SK Telecom plans to transmit quantum keys from Seoul to Busan by installing five units of its repeaters.

After two years of research, SK Telecom said it has successfully developed a quantum repeater for the first time in South Korea, making it the third nation to achieve the next-generation security technology, following the U.S. and China, The Korea Times reported.

Quantum cryptography communication is considered the most secure form of communication encryption that can’t be broken with existing hacking technology. Quantum cryptography is expected to replace the existing security solutions in all areas at risk of data hacking, including national defense, finance, autonomous vehicle and the internet of things (IoT), SK Telecom noted in its release.

Called the Trusted Repeater, the quantum repeater that SK developed can dramatically extend the distance of quantum communication, achieving a distance record of 112 kilometers for Quantum Key Distribution (QKD). Prior to the development of this quantum repeater, the maximum QKD transmission distance was around 80 kilometers due to the fact that it involves the use of weak single-photon quantum signals. The distance limitation of QKD had been viewed as the biggest obstacle to its commercialization.

Now SK Telecom wants to pursue commercial installation, with plans to transmit quantum keys from Seoul to Busan, which is about 460 kilometers, by installing five units of its repeaters. The company will work with its global partners to apply quantum cryptography solutions, including the quantum repeater, to not only to its commercial LTE networks in Korea, but also to commercial networks overseas.

“SK Telecom has opened a new chapter in the field of quantum technologies by developing the Trusted Repeater, an enabler for long-distance quantum communication,” said Park Jin-hyo, senior vice president and head of Network Technology R&D Center of SK Telecom, in a statement. “SK Telecom will continue to focus on developing key quantum cryptography technologies and building a related ecosystem.”

SK Telecom said it applied its quantum cryptography technologies to a commercial LTE network (fiber optic cable) in Sejong City in 2016 and some parts of the advanced science and technology research network (SuperSiReN) in Daedeok Research Development Complex through cooperation with the Korea Institute of Science and Technology Information (KISTI) in May 2017.

SK Telecom has been actively developing core quantum cryptography technologies since it established Quantum Tech Lab in 2011. In February 2017, it entered into an agreement with Nokia to cooperate in the quantum cryptography business and established Quantum Alliance with Deutsche Telekom with the aim to enable secure communication in the age of quantum computing.

Last month, the AT&T Foundry innovation center in Palo Alto, California and the California Institute of Technology (CalTech) announced they were combining forces to form the Alliance for Quantum Technologies (AQT), which aims to speed quantum technology development and emerging practical applications.