[Edaily Reporter Kim Hyun-ah ] KTCorporation(030200)is expanding its quantum cryptography communication network testing nationwide and has begun verifying next-generation quantum communication technology using wireless and satellite networks. The goal is to broaden communication methods and extend transmission distances to enable secure communications even in areas where it is difficult to lay fiber-optic cables.

KTCorporation announced on the 22nd that it has commenced the “2026 Open Quantum Testbed Advancement and Expansion Project,” led by the Ministry of Science and ICT and the National Information Society Agency (NIA). KTCorporation will be responsible for the construction and operation of “Section A,” which connects to existing communication networks in preparation for commercialization, and “Section C,” where next-generation technologies will be tested.

In Section A, a quantum cryptography communication network will be established along the Daejeon–Daegu, Daejeon–Gwangju, Daegu–Busan, and Seoul–Chuncheon routes, centered on the Daejeon hub. The company plans to verify whether the network operates when connecting communication equipment from different manufacturers and to explore potential applications in the financial and medical sectors.

Quantum cryptography is a method of exchanging secret keys—used to encrypt information—via quantum technology. A key feature of this technology is that any attempt to eavesdrop on the information during the transmission of the secret key leaves a detectable trace. However, the actual level of security is also influenced by the configuration of the communication equipment and the overall system.

In some sections, the project will test wireless quantum key distribution (QKD) technology—which transmits light through the air instead of via optical cables to exchange secret keys—as well as methods utilizing satellites. Wireless communication can be used in areas where it is difficult to install cables, while satellite technology can be used to extend quantum communication to distant locations that are difficult to reach using ground-based communication networks alone.

KTCorporation has set a goal of extending the demonstration distance for wireless quantum key distribution—currently about 4.8 km—to 15 km. The corporation is also applying optical technologies to counteract the wavering of light caused by airflow and temperature changes. Additionally, KTCorporation plans to validate technology that allows multiple locations to share a quantum entanglement state. Quantum entanglement is a phenomenon in which the states of two particles are closely linked; the technology for distributing this entanglement across multiple locations is a key area of research for realizing future quantum communication networks.

However, simply increasing the demonstration distance does not guarantee commercialization. Challenges remain, such as ensuring stable communication in real-world environments, achieving interoperability between devices, and managing operational costs.

Jeon Myung-jun, Executive Vice President and Head of the Enterprise Services Division at KTCorporation’s Enterprise Business Unit, stated, “We will support the commercialization of domestic quantum technology by expanding the demonstration environment available to public, private, and research institutions.”