From: droelke@spirit.aud.alcatel.com (Daniel R. Oelke)
Date: Sat, 11 Nov 95 14:02:28 PST
To: ses@tipper.oit.unc.edu
Subject: Re: Who needs time vaults anyway?
Message-ID: <9511112202.AA06738@spirit.aud.alcatel.com>
MIME-Version: 1.0
Content-Type: text/plain


> 
> As for real time-release - how about just using conventional encryption, 
> and require it to be brute-forced?
> 
> Depending on how fine grained you want the release to be, you could also 
> take the inverse of Moore's law, work out how big a key you need to have 
> it unbreakable in less than the desired time, add in whatever fudge 
> factors you feel like based on how much it would be worth to the opponent 
> to get early access, then lock up the secret and throw away the key. 
> 

The problem here is that it is probablistic when they are 
going to be able to unlock it.  If the search space will take a
total of 10 years to exhaustively search, there is a 50% chance
that they will find the key within 5 years, 10% chance that it
will be found in 1 year, etc.  So, if you are lucky, it will
be found in about the time you want it to be.  If you aren't it
will be found in a few milli-seconds.

There is also the problem that your intended recipeient will
need to expend just as much work as your advesary to decrypt
the message.  This might not be a disadvantage in the case of 
a "broadcast" message, but otherwise it might be.

Good idea - but I would say not pratical....
Now, if we just had an objects between 1 and 10 light years away 
that you could bounce lasers off of...... ;-)

Dan
------------------------------------------------------------------
Dan Oelke                                  Alcatel Network Systems
droelke@aud.alcatel.com                             Richardson, TX