As the government unveils its first pan-government “quantum master plan”, attention is focused on whether quantum technology can fundamentally change the national security framework.

The Ministry of Science and ICT’s recently announced “First Comprehensive Plan to Foster Quantum Science and Technology and the Quantum Industry” includes a roadmap for the phased application of quantum technology across the national cryptographic system. The government set a goal of building a national-level “ultra-secure information network” through the plan.

Quantum computers use quantum mechanics, in which multiple states can exist at the same time, going beyond binary calculations of 0 and 1. Conventional computers use “bits” that process all information as either 0 or 1, but quantum computers use “qubits”. While a bit can have only one of two states, 0 or 1, a qubit can handle both 0 and 1. Under this principle of “superposition”, the larger the qubit, the more quantum computing power increases exponentially.

Quantum technology is particularly useful in security. Quantum technologies that can be used for security fall into two broad categories. One is a method that fundamentally blocks the theft of encryption keys during communications through quantum key distribution (QKD). QKD uses quantum mechanics to distribute more complex and secure encryption keys, and is assessed as having a structure that is theoretically impossible to steal.

Another pillar is post-quantum cryptography (PQC). It can be understood as applying cryptographic algorithms that are difficult to decrypt even with quantum computers. As quantum computers’ superposition capability improves, the speed of decryption operations to crack existing cryptography also increases. The industry view is that PQC is a security system that must be introduced to respond to hacking that abuses quantum computers.

Choon-sik Park (박춘식), a former professor in the Department of Cybersecurity at Ajou University, stressed that “PQC corresponds to a new ‘padlock’ that upgrades the security level,” adding that “as the speed of quantum computer development accelerates, the development and transition of PQC technology must take place.”

Internationally, PQC standardisation is under way centred on the U.S. National Institute of Standards and Technology (NIST). The government plans to complete PQC algorithm standardisation early next year and expand pilot transitions centred on major national industries, including communications, defence, finance, transportation and space infrastructure. A Ministry of Science and ICT official said it would foster specialist consulting firms to support the PQC transition and speed up training of related experts.

In the industry, some say the government-led PQC transition should also spread quickly to the private sector. They say the public sector should build up proven cases of applying PQC and use them to encourage private companies to adopt PQC. Still, the cost burden from large-scale system replacement and compatibility issues with existing security systems remain tasks to be resolved.

Park said the government’s plan does not appear to be very late, but stressed that as quantum computing technology development accelerates, efforts should be made to bring forward the timing of field deployment as much as possible, as well as securing PQC technology.

He added that active cooperation from the National Assembly and budget authorities is needed and follow-up measures must support the plan. He said expanding investment in South Korean information security companies to revitalise the quantum security ecosystem would be a more realistic strategy.