making public keys public

[Eric Hughes]

   From: lmccarth at ducie.cs.umass.edu

   If you're not going to make the public key public, why use public key
   cryptography at all ?  Save time and effort and use a symmetric cipher.

You can't do authentication with a shared secret key, because there's
nothing to differentiate the two sides of the link.

In addition, a closely held public key might be held by 10 people;
with secret keys there are 90 different private keys instances to
manage.

Eric