From: hughes@ah.com (Eric Hughes)
Date: Tue, 26 Jul 94 10:41:05 PDT
To: cypherpunks@toad.com
Subject: Forward secrecy
In-Reply-To: <199407261313.IAA03263@zoom.bga.com>
Message-ID: <9407261719.AA05920@ah.com>
MIME-Version: 1.0
Content-Type: text/plain


   One possible hole here is that since they share a commen algorith then
   the algorithm is the 'language' and not the actual messages. 

The algorithm does _not_ completely specify the encoding of plaintext
into ciphertext.  Therefore the algorithm cannot be considered a
language, since it's incomplete.

   There is also the aspect
   of once discovered you could be charged with obstructing justice which
   has very stiff penalties.

I am baffled as to what you could possibly mean here.  It sounds
ridiculous to me.

   They make you participate by giving you immunity in which case you have no
   choice but to reveal it or go to jail. 

This is not what immunity is.  Immunity is given for testimonial
evidence that would be self-incriminating.  By immunizing the witness
before testimony, the testimony, which would then be tantamount to a
confession, is no longer incriminating, that is, the testimony no
longer turns the witness into a criminal in the eyes of the law.  With
the presumption of innocence, it is _conviction_ that makes one a
criminal, not commission of a criminal act.

   While it is true you can't be held in contempt of court for not providing 
   something that doesn't exist they can get you for destroying evidence.

"Destroying evidence" only happens when the materials are destroyed
after they are considered evidence.  If you shred papers that contain
incriminating conversations before anybody asks for them, that's not
destroying evidence, because at the time of destruction the papers
weren't evidence.  This is true even if you think you are under
investigation.  You have no responsibility to cooperate in advance.

Since court proceedings are a highly structured form of social
epistemology (finding out the truth), if there is no proof that
destruction occurred, or insufficient proof that you did the
destruction, there is no conviction.

Consider Sandy's "little brother inside" idea.  What he left out was
the two-hour UPS battery, also inside, so that when seizure happens
the machine can't be turned off.  You'd have to disable the off
switch, of course.

Now, immediately after seizure, you call up the pager inside and
instruct the computer to start wiping disk.  This would be considered
destruction of evidence were it able to be proved that there was data
on it when it left your house, but not when it arrived at the station.
Since when the disk is _first_ looked at, it will be completely
random, there's no proof of alteration.

"What was all that disk activity the whole time?"  "Oh, factoring numbers
takes large amounts of scratch space."

Eric