Why iPhone owners should stop texting Android users amid FBI warning

The FBI is warning iPhone and Android users against texting each other without encryption due to a recent Chinese cyberattack.

On Wednesday, deputy national security adviser Anne Neuberger announced that at least eight U.S. telecom companies had been breached by a Chinese hacking operation known as "Salt Typhoon." The operation accessed private text messages and phone conversations involving an undisclosed number of Americans.

The hackers are believed to have successfully intercepted the communications of senior government officials and high-profile political figures. However, Neuberger said the government did not think "any classified communications" had been accessed.

In response to the attack, the FBI and Cybersecurity and Infrastructure Security Agency (CISA) released guidance aimed at identifying the hackers and preventing future cyberattacks.

Since communications between iPhone and Android users are not encrypted by default, agency officials urged Americans to stop sending texts between the two operating systems or use third-party apps with end-to-end encryption.

Why Aren't Text Messages End-to-End Encrypted?

SMS messaging first emerged in the early 1990s, when there were far fewer concerns surrounding text message security. At this point, altering SMS to include end-to-end encryption would likely be impractical or impossible.

However, modern text messages often do not use SMS and are transmitted using other systems, such as Apple's iMessage and Google Messages.

Are iMessage, WhatsApp, Signal and Google Messages Encrypted?

Text messages between iPhone users and between Android users do include end-to-end encryption by default. However, messages transmitted between the two systems are not encrypted and could be vulnerable.

WhatsApp and Signal both offer end-to-end encryption. NBC News reported on Wednesday that CISA official Jeff Greene and a senior FBI official both urged Americans to use an encrypted app instead of communicating between iPhone and Android devices.

"Encryption is your friend, whether it's on text messaging or if you have the capacity to use encrypted voice communication," said Greene. "Even if the adversary is able to intercept the data, if it is encrypted, it will make it impossible."

This is a developing story and will be updated when more information is available.