> “Work it out” is generally a demand to invent new mathematics, but sadly, mathematics doesn’t work like that.
E2E + a backdoor for a particular police department isn’t the sort of bad idea that requires new mathematics.
> For the last 25 years, engineers have said ‘we can make it secure, or we can let law enforcement have access, but that means the Chinese can get in too” and politicians reply “no, make secure but not for people we like”.
Insecure police departments will inevitably leak the backdoor keys. It's not possible to limit who can use decryption keys based on who they are and not just possession of the keys under our current understanding of how encryption works. If you assume that the police will never leak keys then sure it's easy. But arguing about whether or not social factors like police department computer security is good enough to safely store keys is a technical argument about this technical problem.
It's quite depressing how many people here don't seem able to deconflate "I don't believe police can be trusted with this power" from "it is mathematically impossible to give it to them".
This is a nice clear example of how experts talk themselves into lying to the public for the greater good, as we saw so often in the past :(
Arguing that the myriad local police departments of the United States in particular do not have the security posture required to keep access to a data portal secure is a technical argument against government-backdoor encryption.