News reports about personal data leaks caused by cyberattacks seem to be never-ending.

What’s more, experts warn that advances in quantum computing could eventually make some of today’s encryption technologies much easier to break.

That’s why major technology companies such as Google and Microsoft are working to develop next-generation security technologies.

One of the most promising approaches is quantum cryptography.

Quantum cryptography uses the principles of quantum mechanics to securely share encryption keys.

With conventional communication systems, someone might intercept an encryption key without being detected.
Quantum cryptography, however, can use changes in quantum states caused by eavesdropping to detect signs of interception.

In other words, if someone tries to steal an encryption key, there is a chance that their attempt will be detected.

Pretty amazing technology, isn’t it?

The Japanese Government Is Promoting Quantum Technology as a National Strategy

The Japanese government sees this technology as much more than a research project. It has positioned quantum communication as part of a national strategy involving economic security, next-generation communication infrastructure, and international competitiveness.

Among the 17 strategic sectors identified under “Sanaenomics,” the economic policy agenda associated with Sanae Takaichi, is the quantum technology sector, which includes quantum communication and networks as well as quantum computing.

In 2026, construction began on an approximately 600-kilometer quantum-secure communication network connecting Tokyo, Nagoya, and Osaka.

The government plans to use this network to test and validate the technology, with the goal of putting it into practical use around 2030.

And the ambition goes beyond strengthening Japan’s domestic information security. The government also hopes to develop this technology into an industry capable of exporting its products and services overseas.

In fact, quantum cryptography experiments have been underway in Tokyo since 2010.

At the center of these efforts is the National Institute of Information and Communications Technology (NICT), a national research institute under the jurisdiction of Japan’s Ministry of Internal Affairs and Communications.

Three Major Japanese Companies Are Participating in the Network Project

Three major Japanese companies are playing central roles in the Tokyo–Nagoya–Osaka network project:

• NTT DOCOMO BUSINESS
• Toshiba
• NEC

Of these three companies, Toshiba and NEC have already achieved an important technological milestone in collaboration with NICT.

On July 28, 2025, Toshiba, NEC, and NICT announced that they had successfully demonstrated the coexistence of conventional high-capacity data transmission and quantum key distribution (QKD) in an experimental environment compatible with IOWN, a next-generation optical communication initiative proposed by NTT.

Read the official NICT announcement (July 28, 2025)

Why is this so important?

Because it suggests that we may not need to build entirely new, dedicated communication networks to make quantum cryptography widely available.

If existing optical fiber networks can be used, the cost of introducing this technology could potentially be reduced.

Toshiba’s Quantum Cryptography Technology Is Among the World’s Best

In fact, Toshiba’s quantum cryptography technology has earned a strong reputation internationally.

There are four main reasons for this:

• Extending communication distances, one of the major challenges in quantum cryptography
• Developing technology that generates encryption keys at high speeds
• Enabling quantum communication to coexist with existing optical fiber networks
• Achieving practical deployment in commercial services overseas

One particularly impressive achievement came in 2021, when Toshiba demonstrated quantum key distribution over more than 600 kilometers of optical fiber.

The company has also announced research achievements involving some of the world’s highest quantum key generation rates.

What makes Toshiba especially interesting is that its technology is not limited to laboratory experiments.
It has also been put to use in real-world communication networks overseas, including in the United Kingdom.

Of course, research and development are advancing rapidly in many countries, so this does not mean Toshiba is the world leader in every aspect of quantum cryptography.

Nevertheless, there is no doubt that Japanese companies are making significant contributions to the development of quantum communication technology worldwide.

Toshiba was delisted from the stock exchange in December 2023, so its shares can no longer be purchased through the public stock market.

Still, it’s exciting to see Japanese technology with the potential to compete at the very top of the global market once again!