: From: shirriff@sprite.berkeley.edu (Ken Shirriff)
: Message-ID: <1r24us$oeh@agate.berkeley.edu>
: It seems likely to me that that a large subset of encrypted communications
: would be archived to tape so they could be read if sometime in the future
: probable cause arises and a warrant is obtained.

I think it is unlikely that data like this could be used in court.
Currently LEAs can install wiretaps on large numbers of phones, record
calls without listening to them, and then post-facto obtain warrants
and listen to calls after probable cause is established.  But this
strategy wouldn't get the stuff admitted in court.  (At least, not
in the near term.)

In other words, near as I can tell, the thing that makes such evidence
inadmissable is the interception without a warrant, not the attempt to
interpret what was intercepted without a warrant.  I'd be surprised
that archiving data without consent would be interpreted as anything
but analogous to a wiretap by the courts.

Note that that doesn't mean I think it won't be done if technically
feasible.  Just as I'm sure many wiretaps are done now without
warrants, just to fish for avenues to investigate.  So in the future,
start surveilance, start archiving data, trump up some probable cause,
decrypt post-facto after the warrant is in hand, and the investigation
gets a boost from data that, sadly, won't ever be presented to a jury.

While I'm posting...  for an interesting cautionary tale projecting this
archiving scenario to extremes, read "Lacey and his Friends", a
collection of sf stories by David Drake.  The US starts down the
slippery slope by archiving *everyghing*.  But don't worry folks, it's
stored in a secure repository where nobody but LEAs with warrants can
get to it.  And by the way, we'll be installing cameras on all major
streets.  Hey, this is nothing new, we already have cameras in banks and
teller machines, don't we?

And then we'll pass laws requiring cameras covering *all* public
places.  Then in some private places.  Then we'll make it a crime ever
to be out of range of a camera, except in legally licensed privacy
cubicles.  Only alone.  And with a thorough body search before and
after.  But, see, there's still a right to privacy.  We haven't
curtailed any rights, not really.  And just think how much easier it'd
be to solve crimes in such a situation: just obtain a warrant, put on a
VR helmet and take a walk down memory lane.

And hey, nobody'll be tracking *you* or *me*, no need to be self-conscious.

After all, if you're not doing anything illegal...

Funny, though.  While speeding and the radar detector industry became
pretty much a thing of the past, somehow all this didn't elminate all
crime in the story.  And somehow, politicians got exemptions on grounds
of national security, and rich corporations got exemptions for their
execs on grounds of industrial espionage and the preservation of
competition.  And not everybody was exactly happy with the system.  
I can't imagine why.
