US pushes Facebook for way to peek at encrypted messages

US officials are calling on Facebook not to use snoop-proof encryption in all its messaging services without providing authorities a way to see what is being sent.

The request was laid out in a letter signed by US Attorney General William Barr, along with British home secretary Priti Patel and Australian minister for home affairs Peter Dutton.

"We are writing to request that Facebook does not proceed with its plan to implement end-to-end encryption across its messaging services without ensuring that there is no reduction to user safety and without including a means for lawful access to the content of communications to protect our citizens," read a copy of the letter obtained by AFP and dated October 4.

The letter called on Facebook and other companies to make sure messaging systems were not so well-encrypted that law enforcement couldn't see "content in a readable and usable format" if such needs arose.

The request, addressed to Facebook chief Mark Zuckerberg, raises anew the conflict between technology firms intent on protecting user privacy by scrambling messages with encryption, and government agencies contending that doing so would let evil-doers hide their schemes.

The leading social network already encrypts WhatsApp messages from end-to-end -- meaning only the sender and recipient can read the message, which is saved in encrypted form -- and is working to extend the technology to other apps in its family, including Messenger.

End-to-end encryption already protects the messages of over a billion people every day, according to a Facebook.

"It is increasingly used across the communications industry and in many other important sectors of the economy," Facebook said in response to an AFP query.

"We strongly oppose government attempts to build backdoors because they would undermine the privacy and security of people everywhere.