For example: I’d be very curious to learn about the actual mechanism by which the supposed “_NSAKEY backdoor” would work. I’m not interested in the private key if that’s what you mean by method :)

AFAICT it doesn’t, you can’t hit those code paths unless you already have access to the machine.

(This is a pretty unfair example though, _NSAKEY is the “Bush did 9/11” of backdoors.)