The guidance was issued after Chinese Communist Party-linked hackers targeted U.S. telecommunications systems.
A federal agency on Wednesday issued urgent written guidance to top government officials and politicians to immediately stop using standard phone calls and text messages after major U.S. telecommunications companies were targeted by Chinese hackers.
The Cybersecurity and Infrastructure Security Agency (CISA) said in guidance that “individuals who are in senior government or senior political positions” should “immediately review and apply” best practices around using smartphones.
“Use only end-to-end encrypted communications,” it said, saying that these “highly targeted individuals” also “should assume that all communications between mobile devices—including government and personal devices—and internet services are at risk of interception or manipulation.”
End-to-end encryption refers to data protection that makes information unreadable except for the sender and its recipient. A number of chat apps including WhatsApp, Signal, iMessage, BrightChat, and others already have end-to-end encryption.
Regular phone calls and text messages are not end-to-end encrypted, meaning they can be monitored, either by telephone companies, law enforcement, or potentially by hackers.
The warning follows a prior notice issued by the FBI and CISA earlier this month that Americans should opt to use encryption. Wednesday’s guidance specifically tells high-level government and elected officials to quickly start using it.
Previously, CISA warned that Chinese regime-linked hackers known as “Salt Typhoon” have hacked into U.S. telecommunications systems and may be able to obtain sensitive data on individuals.
That message was reiterated on Wednesday, with CISA executive assistant director for cybersecurity Jeff Greene telling reporters that the government’s investigation into the breach is ongoing and various targeted agencies and people are at different stages of their response. Based on his comments, it’s not clear whether Chinese hackers are still lurking within U.S. telecommunications companies’ systems.
Salt Typhoon’s compromise “is part of a broader pattern of [Chinese regime] activity directed at critical infrastructure,” Greene said, referring to Chinese-linked cyber operations focused on utilities and other sensitive networks and tracked under the nickname “Volt Typhoon.”
“This is ongoing [Chinese regime] activity that we need to both prepare for and defend against for the long term,” he said.
