China uses quantum satellite to protect world’s largest power grid against attacks
- Operation commands able to be sent using particles of light relayed by Mozi, the world’s first quantum satellite
- It offers reliable protection against blackouts caused by hacking, especially for commands sent over long distances or without optical fibres
Part of the network links the power grid of Fujian, the southeastern province closest to Taiwan, to a national emergency command centre in Beijing.
In a drill conducted in May, the ultra-secure communication line allowed central government staff to take over control of the coastal province’s power grid operation without their commands being vulnerable to tapping or manipulation by a third party.
Beijing and Fujian are almost 2,000km (1,243 miles) apart. Building an optical cable of that length for quantum communication could be expensive, according to researchers working for the State Grid Information and Communication Branch – an agency building the national power grid’s information infrastructure.
China launched Mozi in 2016 for scientific experiments, but in recent years the satellite has found a growing number of civilian and military applications.
Applying quantum communication technology in the energy sector was prompted by national security concerns, lead scientist Zhao Ziyan and his colleagues said in a paper published last month in industry journal Electric Power Information and Communication Technology.
China has the world’s largest national power grid, which last year transmitted 7,500 terawatt hours of electricity – more than the grids of the United States, India, Russia and Japan combined.
The country has also built up the world’s largest renewable energy infrastructure, including wind and solar farms, and has more electric cars and smart recharging stations than anywhere else.
This made China’s power grid the most sophisticated and difficult to operate, according to Zhao and colleagues.
If a hacker were to infiltrate the power communication network and decode the commands, they could cause large-scale blackouts or other damage, Zhao’s team said.
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The quantum satellite proved an effective solution to this problem, especially for communication over long distances or in locations without optical fibres.
In theory, it would allow the government to maintain control over power supply facilities all over the country with high confidence and relatively low cost, according to the researchers.
Mozi could effectively pick up entangled particles of light beamed from the roof of the Beijing command centre. At the receiving end, a mobile station could pick up the quantum information relayed by the satellite and pass it to the local power grid computer.
If a third party managed to intercept some light particles, it would change the physical state of other particles in the chain and trigger an alert.
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Mozi’s capacity to secure the network could be improved upon, given its limited bandwidth, the research paper said.
Furthermore, converting quantum information to the codes used in power transmission is complex and time-consuming, and the satellite link could be established only when the satellite was passing overhead – with the quality of light signals also affected by the sun or clouds.
China is developing next-generation quantum satellites that could form a global constellation and work effectively in the daytime, with laser communication bandwidth reaching several gigabytes per second, according to openly available information.
The government in Beijing also has an optical cable to Shanghai to strengthen its control of power management in the nation’s richest city.
Some overseas power grid operators, too, are using China’s quantum technology to strengthen their defence against sabotage attempts, according to Zhao and colleagues. They did not name the countries.
The application of quantum technology has brought some unexpected changes in the operation of China’s power grid, according to some industry experts.
Certain critical operations, such as the on-off switch of a backbone network, could previously only be carried out manually, owing to security concerns. Thanks to the increased safety of quantum communication, these operations began to be mechanised, reducing the switching time from hours to seconds, the experts said.
Other sectors, including high-speed rail, were introducing quantum technology into their communication networks to improve safety and performance, according to researchers involved in those projects.
Quantum communication was once regarded as a technology of little practical value. But the recent rapid development of quantum computers with potential for code-breaking has prompted more than a dozen countries, including the US, to join China in the race.
