From: kentborg@world.std.com (Kent Borg)
Date: Fri, 10 Jun 94 21:03:26 PDT
To: hughes@ah.com
Subject: Re:  Delayed self-encrypting messages
Message-ID: <199406110402.AA13528@world.std.com>
MIME-Version: 1.0
Content-Type: text/plain


>An interesting research project would be to construct one of these to
>sit in orbit.

And I would even trust it to be pretty safe from physical tampering.
The cost would be so high and the exposure from various space watchers
rather certain.  Good enough for me.


Seems there are two ways so far mentioned to do this "embargo" trick:

1) Have a trusted and secure party hold your key until time.

2) Hide a key inside an expensive computation and then figure out how
to get the NSA *really* interested in finding and publishing their
crack of your code.  If you estimated their abilities correctly your
fuse will burn at the right speed, the time delay will be as you
intended.  (Gosh, is there a thriller novel in here some place?)

I think I see a third:

3) Kinda "security through obscurity", but a dollop of "trusted" third
party too.  

  a) Encrypt the key and instructions for its distribution with
Trent's public key.  

  b) Add a message asking him not to open 'til Christmas.  Encrypt
again with his public key.  

  c) Send it off on a remailer-goose chase to delay and further
confuse the TLAs.

Hell, maybe just skip "c".  


Or...

Split the key into a n-of-m set of sharing fragments.  Send each off
to each of m Trent's.  Hope that no more than m-n get lost, hope that
the TLAs can't find/turn n of your Trents.


-kb, the Kent who isn't as devious as he would like to be--but he is
still reading cypherpunks.


--
Kent Borg                                                  +1 (617) 776-6899
kentborg@world.std.com                                
kentborg@aol.com                                      
          Proud to claim 28:15 hours of TV viewing so far in 1994!