DC-Net proposal, comments requested

[hughes@ah.com (Eric Hughes)]

>Doug Barnes writes about Tim Newsham's work on DC-Nets:

>> I've been looking at this problem as well, Tim, and it doesn't seem to 
>> me that you have to output a bit at a time. 

Indeed, the DC-net protocol operates in any abelian (commutative)
group, such as, say, integers mod 2^56 (the size of a ping packet
body).  The modulus need not be a power of two, but there's little
advantage if it's not.  The vectors in a linear code might also be
appropriate for certain side effects.

>[... some people] consider even using
>ciphers to generate the tosses, though then the DC-Net ceases to be
>information theoretically secure and is no more secure than the cipher
>itself.

In practice, this is a small problem.  Since many of the messages that
a deployed DC-net sends out will be text encrypted for some particular
destination, one needs no greater computational security than that of
the cipher used to encode the message.

There are several random number generators provably as secure as the
hard number-theoretic problems used for public key cryptography.  The
problems include quadratic residuosity, factoring, and discrete log.

Eric