China Imposes New Security Curbs After Alleged Supercomputing Data Breach

The compromised data may include highly sensitive materials related to missile design, aerospace research, and nuclear fusion simulations.

Security officials walk along a hallway at the Great Hall of the People amid preparatory meetings for the third session of the 14th National People's Congress in Beijing on March 4, 2025. Pedro Pardo/AFP

The Chinese Communist Party (CCP) has imposed sweeping new security restrictions across government agencies following reports that a major national supercomputing center was hacked, potentially exposing vast amounts of sensitive data, according to people familiar with the matter.

The measures—ranging from bans on mobile phones in offices to tighter controls on networked devices—reflect what analysts and insiders describe as a significant escalation in Beijing’s efforts to prevent data leaks, particularly amid concerns about both external cyberthreats and insider risks.

Several China-based insiders spoke to The Epoch Times on the condition of anonymity out of fear of reprisal.

Phone Bans and Offline Mandates

An individual with knowledge of the regime’s operations told the publication that the CCP’s General Office of the State Council recently issued a series of directives aimed at tightening information security.

Under the new rules, employees must switch off or silence their phones before entering office areas and store them in designated signal-blocking lockers at building entrances. Staff are also required to undergo additional checks to ensure they are not carrying secondary devices—a measure designed to prevent workers from concealing backup phones.

In offices, communication is to be conducted via landlines, while printers and other terminal devices are prohibited from connecting directly to the network.

A second source, who works in a government department handling sensitive matters, told The Epoch Times that security protocols have been further intensified in units relating to foreign affairs and national defense. These offices have introduced mobile signal detection systems and require certain operations to be conducted entirely offline.

“Authorities have repeatedly stressed that internal work must be handled in a ‘disconnected’ environment,” the source said, adding that some highly sensitive computers are now barred even from internal networks and must operate as fully isolated machines.

The new restrictions are being rolled out alongside expanded cybersecurity training programs across multiple regions, including guidance on identifying phishing emails and limiting the use of virtual private networks (VPNs), according to officials and internal notices.

A retired civil servant told The Epoch Times that the scale of the latest measures reflects a notable shift.

“Security controls have always existed, but enforcement has clearly intensified,” the civil servant said. “There were restrictions a decade ago on using iPhones in offices, but enforcement eased over time. Now the ban has been reinstated and expanded to include domestic devices as well.”

The inclusion of Chinese-made smartphones reflects growing concern about potential vulnerabilities, the civil servant said, noting that even domestically developed operating systems may still carry security risks.

Regime officials appear to view modern smartphones, which can gather data with cameras, microphones, and sensors, as difficult to fully secure.

Alleged Breach at Supercomputing Center

The heightened controls followed a CNN report on April 8 that China’s National Supercomputing Center in Tianjin had suffered a major cyberintrusion, involving data leaks exceeding 10 petabytes.

According to the report, the compromised data may include highly sensitive materials related to missile design, aerospace research, and nuclear fusion simulations. The Chinese regime has not publicly commented on the incident.

The National Supercomputing Center did not respond to The Epoch Times’ request for comment.

A Nanjing-based network engineer told The Epoch Times that the scale of the alleged breach in the CNN report suggests the possibility of insider involvement.

“Facilities like supercomputing centers typically have multiple layers of authentication and alert systems, making direct external penetration extremely difficult,” the engineer said.

“If mobile devices were compromised, they could potentially be used as intermediaries to collect or transmit data.”

He said that smartphones could function as surveillance tools if infected with malicious software, enabling hackers to access cameras, microphones, and other sensors. Even routine communications could be aggregated into valuable intelligence, he said.

Expanding Controls

The tightening of security measures is not limited to the CCP’s central government agencies. Local governments and telecom operators across the country have recently issued notices requiring companies to seek approval for cross-border network connections.

The regime has also begun campaigns to identify and shut down unauthorized international data links.

The network engineer said the moves indicate a broader effort to reduce exposure to external networks.

“Officials are concerned about vulnerabilities in VPNs and the use of foreign digital tools by internal staff,” he said. “By restricting unapproved cross-border connections, they are trying to minimize the risk of outward data flow.”

Shao Rong contributed to this report.