Cameron’s legislation has not happened, and there’s a simple reason; encryption is a binary. Either something is encrypted, and thus secure from everyone, or it’s not. As the security expert Bruce Schneier has written: “I can’t build an access technology that only works with proper legal authorisation, or only for people with a particular citizenship or the proper morality. The technology just doesn’t work that way. If a backdoor exists, then anyone can exploit it.”
That’s the crux of the problem. While you can legislate to only give state agencies access to terrorists’ communications, and with proper oversight and authorisation, you cannot actually build encryption that works like that. If you put a backdoor in, it’s there not just for security services to exploit, but for cyber-criminals, oppressive regimes and anyone else.
There is no way around this. Either we can say that end to end encryption is legal or that it is illegal. There is no way to have it being legal but not really encryption…..