Re: @Repeat (pete 2) The law is not the answer
Thing is, what if the government you describe gets overthrown and the new leader(s) simply say, "Unlock everything or your family will have never existed." The main problem with your system is that it has to rely on perfect trust. Once the trust is broken, anywhere along the line, it's in the open again.
That's always been the big problem with encryption. At some point, for the data to be usable, it has to be DEcrypted. and that's where you're most vulnerable, because THIS is where trust comes in.
Thing is, we're just about at a point where you can't trust ANYONE. Which means it can all boil down two one of two scenario. Either we go into total paranoia, and all socialization will cease because we can't trust anyone, or we surrender to the inevitable result of a world where trust cannot be guaranteed: sooner or later (usually sooner), no secret will be safe and pray that civilization doesn't hinge on a secret.