Protecting governments against quantum computing attacks

As quantum computing continues to advance, current encryption standards are being rendered inadequate and insecure.

These security standards are largely based on the idea that classical computers cannot perform the calculations needed to crack encryption keys in a practical timeframe. Research suggests that quantum computers, which can perform these calculations more quickly by several orders of magnitude, will be able to break current encryption methods in a far shorter space of time.

Governments and other public organisations hold some of the world’s most sensitive data, which is in fact already at risk. ‘Harvest now, decrypt later’ attacks involve malicious actors intercepting protected transmissions now, and then decrypting them when the technology becomes available. Governments are at particular risk as much of the data they hold needs to be protected long into the future.

Quantum Key Distribution (QKD) is a quantum-safe solution that protects sensitive data today and in future by using the fundamental principles of quantum physics. It will not only protect data when quantum computers are more widely available, but also from the ‘harvest now, decrypt later’ attacks being carried out today.

Toshiba's QKD technology utilises the quantum properties of light to generate secure random keys for encrypting and decrypting data. Keys are delivered via individual photons sent along the network. Any attempt at interception disturbs the quantum state of the particles, revealing the intrusion and causing the system to discard any intercepted key material, maintaining the integrity of the data.

‘Harvest now, decrypt later’ attacks can occur while data is in transit. ‘Data in transit’ is one of the three ‘states’ of data, during which it requires specific protections. While the others, ‘at rest’ and ‘in use’, typically describe data housed in one location, data in transit is vulnerable to certain high-security threats like eavesdropping attacks and data theft while it’s in motion between points.

In order to secure data in transit against such attacks, networks need to be resilient against decryption attempts. That’s one reason why QKD technology is so successful at ensuring data security, as the quantum secure signals can mitigate eavesdropping attempts, meaning that the transmissions cannot be decrypted, and the network is secure.

At Toshiba, we bring over two decades of quantum cryptography leadership to our QKD solutions, providing superior performance and a practical approach to integrating QKD into existing communications networks. We are already working with public sector organisations such as the Austrian Institute of Technology to test and develop applications of QKD within the public sphere.

Yes, Toshiba has developed QKD systems that can be seamlessly integrated into existing networks. They offer long-range data transmission capabilities and multiplexing technologies that allow for the coexistence of QKD signals and conventional data traffic on the same fibre infrastructure.

QKD works by encoding encryption keys onto individual photons. Due to the laws of quantum physics, any attempt to observe the particles affects their state, meaning attempts to eavesdrop are automatically detected and mitigated. The key material is not used, preventing the eavesdropper from intercepting and using any encryption keys.

As QKD uses the actual physical properties of particles for protection, any attempt at using either mathematics or quantum computing cannot decrypt QKD quantum secure keys – QKD is immune to maths or quantum computing-based decryption and is therefore truly quantum-secure.

Due to its reliance on the laws of physics, QKD is provably secure, with the UK’s National Physics Lab independently validating the critical parameters of Toshiba’s QKD systems.

PQC refers to emerging software and mathematics-based encryption standards that are believed to be resistant to attack by quantum computers. As PQC is software and mathematically-based, it may be susceptible to future compromise by quantum computers.

QKD and PQC can be deployed together within a network to benefit from the respective benefits of both systems to provide a ‘defence in depth approach’.