From: Anders Sandberg (asa@nada.kth.se)
Date: Sat Aug 31 2002 - 14:21:45 MDT
On Sat, Aug 31, 2002 at 10:07:00AM -0700, spike66 wrote:
> Anders Sandberg wrote:
>
> >>If we assume some unexpected breakthrough allows useful (hundreds or
> >>thousand bit quantum computers) then you could start doing discrete
> >>logarithms, and it would be a boon to NSA et al. Still, the main problem
> >>is the sheer amount of data; just opening up files of known suspects and
> >>people under investigation would likely keep various agencies extremely
> >>busy...
> >>
> Understatement. If some quantum miracle allowed instant factoring of
> any number, a new and better security technique would be to bury your
> unencrypted signal (the needle) in tons of straw. One could download
> the entire extropians archive and send out the entire thing with each
> message. The receiver would be notified beforehand which words to
> search for. The NSA would be overwhelmed. spike
Actually, that is not very secure. Running a diff between the archive
and the post would reveal where the differences are, and then it would
be just a matter of figuring out what differences are relevant. It is a
bit like the earlier steganography thread. A more elegant method is
chaffing (http://theory.lcs.mit.edu/~rivest/chaffing.txt), which seems
to be more useful and powerful.
Then there is disinformation. By constantly generating different kinds of
alarm-inducing information the usefulness of scanning becomes less.
However, this requires some knowledge of what would be disruptive to
data-gathering. The old NSA line ("Bomb President Mossad TNT CIA...") is
likely no match for a context-sensitive program. Instead one has to
generate messages that fit the same profile as the *real* message one
would want to send, and then do that as a matter of course.
One time pads are still unbreakable in a post QC world, but a pain to
distribute. The real use of RSA and the other quantum-sensitive cryptos
are the "post cold war" civilian uses of crypto in trade and
authentification.
-- ----------------------------------------------------------------------- Anders Sandberg Towards Ascension! asa@nada.kth.se http://www.nada.kth.se/~asa/ GCS/M/S/O d++ -p+ c++++ !l u+ e++ m++ s+/+ n--- h+/* f+ g+ w++ t+ r+ !y
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