[pc2g4d]

But with backdoored encrypted communications the government would have instant access to ALL enciphered letters at once, regardless of the seeming guilt or innocence of the sender or recipient.

To me that seems like the key difference. If all but face-to-face communications are electronic, and no electronic communications can be strongly encrypted, then the private sphere is greatly reduced and many things once considered private become public.

But on the other side of things, with strong crypto many things once considered public would become private.

There doesn't seem to be an easy way around this choice.

[tptacek]

Hold on. With status quo electronic communications in the 80s and most of the 90s, the government retained instant access to communications for investigative purposes, and no serious objections were raised --- just as nobody objects to the idea that the police, searching your house with a warrant, get instant access to letters you've left on your desk.

Instantaneity can't be the fulcrum of this debate, because it's been the norm since the beginning of English common law.

There has to be some other principle at stake that can argue against decryption backdoors. And I think there are such principles! But I think it's important that they be articulated carefully.

[pc2g4d]

Yes, in previous decades the government could access electronic communications under the third party doctrine[1] that says the fourth amendment only applied to "papers" held by the individual / in their home, not to communications voluntarily placed in the hands of a third party. On the other hand, far less of people's lives was conducted online. I expect that's why no real objections were raised.

Because much intimate communication has moved from in-person/on-telephone/other-instantaneous communications to asynchronous platforms hosted by third parties, in effect much that was "private" is now effectively "public". What once required a warrant now does not. Many things previously subject to protections against unreasonable searches are no longer so protected.

[1]: http://www.abajournal.com/magazine/article/the_data_question...