Lot's of one-time-pads available for $15 each! [was: Nth digit of PI]

[Steven D. Majewski]

On 16 Jun 2000, Aahz Maruch wrote:


> Close, but no cigar.  What you're describing that's vulnerable is the
> use of a book as an encryption key rather than a one-time pad.  If it
> were literally a one-time pad, there'd be no particular physical marks.
> Of course, I don't think the concept of a one-time pad existed as such
> back then.

  Well -- the concept of one time pads goes back to the 1920's or earlier,
and the ones the German's used were written down on paper -- the "one
time" implied that they were destroyed after they were used. 
  It's a modern day computer notion that even better than a real physical
pad of paper that can be intercepted or stolen, is a shared algorithm that 
generates a random one time pad. 
  But your "Close, but no cigar" comment is justified on other grounds: 
the one time pad is supposed to be random, and using a non random pad 
makes it theoretically vulnerable. I just wonder how practically 
vulnerable it is, given a extremely large choice of non-random bit-streams
to choose from. 

 I believe the idea of using a book text as an easily shared but very
large key is a pretty ancient idea --certainly predating the one-time pad.
Does anyone have a reference ? I can't remember where I first saw it 
mentioned. 


-- Steve Majewski 
   Cut wood, carry water.