With a precision of being off by no more than 1 second in 60 million years, "Beijing Time" is facing a "silent war."

Recently, the national security authorities cracked a major cyber - attack case, obtaining irrefutable evidence of the cyber - attack and intrusion into the National Time Service Center of China by the US National Security Agency (NSA), foiling the US's plot of cyber - attacks, espionage, and sabotage, and making every effort to safeguard the security of "Beijing Time".

Investigations revealed that the NSA's cyber - attack activities against the National Time Service Center had been premeditated for a long time, showing progressive and systematic characteristics. For example, from August 2023 to June 2024, the NSA specifically deployed a new cyber - warfare platform and activated 42 special cyber - attack weapons, launching high - intensity cyber - attacks on multiple internal network systems of the National Time Service Center of China. It also attempted to horizontally penetrate into the high - precision ground - based time service system and pre - set the ability to paralyze and damage it.

The national security authorities found that the NSA's cyber - attack activities were mostly launched from late night to early morning Beijing Time. It used virtual private servers in the US, Europe, Asia and other regions as "springboards" to conceal the source of the attacks, bypassed anti - virus software by forging digital certificates to hide the attack behavior, and used high - intensity encryption algorithms to deeply erase attack traces. It resorted to every possible means to carry out cyber - attack and infiltration activities.

This is a silent war against "time sovereignty".

"Beijing Time" is broadcast from here

Many people may hear the name "National Time Service Center" for the first time. In fact, the "Beijing Time" we hear every day comes from the National Time Service Center of the Chinese Academy of Sciences (hereinafter referred to as the "National Time Service Center") located in Lintong, Xi'an, Shaanxi.

Source: National Time Service Center

Why is "Beijing Time" broadcast from Shaanxi? There is a historical origin behind this.

On September 28, 1949, Beijing Xinhua Radio Station first broadcast the time of the East Eighth Time Zone, "Beijing Time", via radio waves. Later, the Shanghai Astronomical Observatory of the Chinese Academy of Sciences rented a short - wave radio station for time service, mainly based on the astronomical time jointly measured and maintained by various observatories.

In the 1960s, with the urgent need for accurate time in national defense construction and economic development, the state decided to build a time service station in the inland hinterland. Shaanxi is located in the heart of China, where the signals can cover the whole country. Moreover, the Qinling Mountains serve as a natural barrier, which can ensure security and facilitate communication.

Pucheng Long - wave Time Service Station. Source: National Time Service Center

In 1966, the Shaanxi Astronomical Observatory located in Pucheng County, Shaanxi Province, began construction and started short - wave time service in 1971. The completion of the short - wave time service station enabled China to have the land - based radio time service ability to cover the whole country. On this basis, a small - power test station of the long - wave time service station started trial broadcasting in July 1976. Only four months later, the time service signals were broadcast regularly every day. Since then, China's standard time has truly had its own "benchmark sound".

Time service accuracy of "no more than 1 second deviation in 60 million years"

The so - called "time service" refers to distributing the standard time to industries such as communication, power, transportation, surveying and mapping, aerospace, and national defense through means such as Beidou satellites, short - waves, long - waves, telephones, and the Internet. Then these systems calibrate their own clocks.

The generation of "Beijing Time" is inseparable from atomic clocks. In 1967, to improve the accuracy of time measurement, the 13th General Conference on Weights and Measures revised the definition of the time unit "second", changing from the astronomical "second" reflecting the Earth's rotation state to the atomic "second" measured by the internal electromagnetic oscillation period of atoms. Since then, scientists around the world have begun to compete in developing atomic clocks that can accurately measure and maintain time, that is, atomic frequency standards.

Atomic clocks use signals generated by internal quantum transitions of atoms for time measurement and can be divided into time - keeping atomic clocks and reference atomic clocks. Time - keeping atomic clocks have strong environmental adaptability and can operate continuously and reliably for years, used for continuously generating and recording time signals; reference atomic clocks are more accurate.

In 2005, Professor Zhang Shougang was assigned to the National Time Service Center to start research on high - performance atomic clocks in China. After 15 years of efforts, Zhang Shougang's team successfully developed two cesium atomic fountain reference clocks with independent intellectual property rights in 2020, enabling "Beijing Time" to have its own calibration ability.

Now, China has more than 40 different types of time - keeping atomic clocks, continuously and stably generating standard atomic time. Through the calibration of cesium atomic fountain clocks, the National Time Service Center can generate stable and accurate atomic time. For a long time, the national standard time generated by the National Time Service Center has ranked among the top in terms of global accuracy. Since 2024, China's time service accuracy has ranked first in the world, reaching no more than 1 second deviation in 60 million years.

Cesium atomic fountain clock. Source: National Time Service Center

What impact will an attack on "Beijing Time" have on our lives? Wei Dong, the deputy director of the General Office of the National Time Service Center of the Chinese Academy of Sciences, once said: If there is a one - millisecond time difference, the substations will have a timing disorder, resulting in large - scale power outages; if there is a one - microsecond time difference, there may be a change of hundreds of billions in international stock market transactions; if there is a one - nanosecond time difference, that is, one - billionth of a second, the positioning accuracy of Beidou will be off by 30 centimeters, and it will also affect people's daily communication, as the radio carriers cannot be synchronized, and mobile phone calls and Internet access cannot be realized; if there is a one - picosecond time difference, that is, one - trillionth of a second, there will be a deviation of several kilometers in the positioning of the lunar soil collection vehicle and the Chang'e spacecraft, which may prevent Chang'e from returning successfully.

The US chose late at night Beijing Time, concealed its tracks through "springboard" servers in multiple locations around the world, and used advanced technologies such as "zero - day vulnerabilities" (security vulnerabilities that are maliciously exploited immediately after being discovered) to break through the defense lines. Its intention is obvious: to destroy the time benchmark, paralyze China's key infrastructure such as finance, power, and communication, and thus contain China's scientific, technological, and economic development.

The Beidou system empowers "Beijing Time"

In ancient times, people used morning bells, evening drums, and night - watchmen to "announce the time" and convey time. Currently, there are various time - service methods, including radio time service (long - wave time service, short - wave time service, low - frequency time - code time service), network time service, and satellite time service. Satellite time service uses artificial satellites to broadcast standard time information. It is the latest and most accurate time - service method at present, bringing a qualitative leap to various fields that require precise time.

The Beidou Navigation Satellite System (Beidou system for short) is a global satellite navigation system independently developed and operated by China. Many people know that it can be used for positioning and navigation. In fact, the Beidou system also has a very important function, that is, satellite time service.

Source: Official website of the Beidou Navigation Satellite System

Currently, there are four satellite time - service systems in the world. In addition to China's Beidou system, there are also the US GPS system, Russia's GLONASS system, and the EU's Galileo system.

According to an article on the WeChat official account of the "Institute of Physics, Chinese Academy of Sciences", the time - service accuracy of Beidou can reach the order of 10 nanoseconds. The Beidou navigation satellites are equipped with on - board atomic clocks to ensure that the Beidou time - service system has an accurate time source. The navigation satellites broadcast signals carrying accurate standard time information and satellite position information. The receivers can correct the local time by calculating the clock difference between themselves and the satellites, thus completing the time service. In short, after users receive the Beidou broadcast signals, they can independently correct the time difference between the local time and the standard time to achieve time synchronization. Navigation satellites such as GPS also use this time - service method.

With the Beidou system, it means that the Chinese people can better keep the precise time in their own hands.

This article is from the WeChat official account "IT Times" (ID: vittimes), author: Jia Tianrong, published by 36Kr with authorization.