Well, that does actually make some schemes impossible (in a pi = 3 kind of impossible) because it means the private key has to leave someone’s device and be sen

Well, that does actually make some schemes impossible (in a pi = 3 kind of impossible) because it means the private key has to leave someone’s device and be sent over the wire- and many schemes don’t do that. https://en.m.wikipedia.org/wiki/Three-pass_protocol https://en.m.wikipedia.org/wiki/Three-pass_protocol I’m not a cryptographer but I assume there are other schemes that are at least weakened by the requirement of a third party holding a key, much like the TSA master lock program was broken by statistical analysis of locks that were mastered this way. But the mathematical impossibility if this aside, there is a very real practical impossibility if trusting an organization as large as the US government to keep such a database secure. There are better ways to help law enforcement than blowing such a large gaping hole in the web.