The officials argued that the approach would avoid weakening encryption, which is a way to encode messages, and claimed that it would not be any more intrusive than older technologies used by spy agencies to snoop on telephone lines.
The letter sent to GCHQ this week was signed by seven tech companies, 23 civil society organizations and 17 experts in digital security and policy. It said that the “ghost proposal” put forward by the two spy agency officials would violate “import human rights principles.”
“This proposal to add a ‘ghost’ user into encrypted chats would require providers to suppress normal notifications to users, so that they would be unaware that a law enforcement participant had been added and could see the plain text of the encrypted conversation,” the letter stated.
When asked for comment on Thursday, the UK National Cyber Security Centre responded with a statement from Levy in which he said the proposal was always “intended as a starting point for discussion.”
“We welcome this response to our request for thoughts on exceptional access to data — for example to stop terrorists,” he said. “We will continue to engage with interested parties and look forward to having an open discussion to reach the best solutions possible.”