KT to Transmit Wireless Quantum Cryptography Communication up to 10km Next Year... Satellite and Transceiver

KT will extend the wireless quantum cryptography communication data transmission and reception distance to about 10 km using domestic technology by 2024. It is expected to securely exchange information even with low Earth orbit satellites beyond the atmosphere.

Lee Young-wook, Senior Executive Director of the All Optic Network Task Force (TF) in charge of Future Technology Network at KT Convergence Technology Institute, stated at a press briefing on the 12th, "If the wireless quantum cryptography communication distance is extended to 10 km, encryption keys can be delivered from satellites."

Lee Young-wook, Executive Director at KT, is explaining quantum cryptography communication technology.
[Photo by KT]

The emergence of quantum computers that can break codes in 1 second, which previously took 3,300 years with conventional computers, has increased the necessity of quantum cryptography communication. Current encryption systems can be neutralized to steal information. On the other hand, when information is sent via quantum cryptography communication, only those with the encryption key can access the data. If leaked in the middle, the state changes, immediately revealing the hacking attempt.

Especially, the use of radio interference as a weapon in the Ukraine war has heightened the importance of quantum cryptography communication. Currently, wireless communication is cut off when interference signals are sent, making it impossible to control weapons like drones. Moreover, if urban air mobility (UAM) and other transportation means become commercialized, radio waves could be exploited for terrorism. The wireless quantum cryptography communication being developed by KT can ensure network stability and be applied to moving objects such as unmanned aerial vehicles and military reconnaissance satellites, aiding the military's advanced strategization. It can also be utilized in marine, island, and mountainous areas where fiber optic cable connections are difficult.

KT began research and development (R&D) on quantum cryptography communication in 2018 and is developing wireless quantum key distribution technology. This year, it succeeded in a demonstration transmitting encryption keys over a 2 km section crossing Gapyeong Cheongpyeong Lake. Lee said, "There were restrictions on the experimental location. According to calculations, transmission up to 4 km is possible." As the transmission distance increases, atmospheric effects such as wind increase, and the precision of transmission and reception devices decreases. KT has made the transmission and reception devices capable of ultra-precise semi-automatic alignment instead of manual.

Next year, KT plans to extend the transmission distance to 10 km. This is the distance from the ground to the atmosphere and the point that must be reached for commercializing quantum cryptography communication between satellites and the ground. Above 10 km altitude is a vacuum state, so there is no data loss. The ultimate goal is to expand the radius to 20 km for use in military operations.

To achieve this, KT is collaborating with domestic partners to develop the technology. Lee said, "Eavesdropping has become common even among allied countries. Foreign equipment often includes backdoors, raising security concerns. Also, domestic production allows for a system that can be quickly repaired in case of failure." KT is expanding the quantum cryptography communication ecosystem by transferring core technologies of its self-developed quantum key distribution devices to domestic SMEs such as Woorinet and Kowiver.

In the long term, the technology will be applied to the security of urban mobility such as UAM, unmanned aerial vehicles (UAVs), drones, as well as high-altitude long-distance moving objects like aircraft and satellites. Lee said, "We will protect the safety of communication infrastructure with a dense quantum cryptography security system covering both sky and land."