> The problem is, how do you build a back door that can only be used by people with valid (and just) warrants?
That's an interesting technical problem. A lot of people dismiss it as impossible out of hand, but they are underestimating what you can do with modern cryptography.
You make it a distributed back door that requires several independent third parties to cooperate to use it.
You choose the third parties so that no particular warrant seeker will be able to get enough power or influence over enough of the third parties to force them to enable the back door unless they think the use is valid and just. (You can actually design it so that the warrant seeker does not know who the third parties are).
Some aspects of this may be too complicated to be practical, but it is not impossible.
That's an interesting technical problem. A lot of people dismiss it as impossible out of hand, but they are underestimating what you can do with modern cryptography.
You make it a distributed back door that requires several independent third parties to cooperate to use it.
You choose the third parties so that no particular warrant seeker will be able to get enough power or influence over enough of the third parties to force them to enable the back door unless they think the use is valid and just. (You can actually design it so that the warrant seeker does not know who the third parties are).
Some aspects of this may be too complicated to be practical, but it is not impossible.