General Response:  We wish to thank all of the referees for their comments
and have made the requested corrections and clarifications, as described
below.

Response to the Editor:
As requested, we have made reference to the common 
heritage of Gateway and the Mississippi Portal.  This is included in
the introduction.  Also, because of
problems with the PDF version, I am attaching
the tex source, images, postscript, and pdf of the paper all as a tar file.

Response to Referee 1:
We have corrected the indicated typos.

Response to Referee 2:
No corrections requested.

Response to Referee 3:
When the paper was written, the Charon security solution was in place and
the SSL solution was under development.  Since then we have completed
and thoroughly tested the
SSL solution, and have had it approved for user testing by the 
HPCMO security team. The
SSL solution lived up to our expectations for ease of use and deployment,
so it is our current security method.  These things were not yet verified
at the time of writing.  We have clarified the security discussion on these
points.

We also apologize for any difficulty viewing the pdf document.  The
paper was written in latex and the postscript was converted to pdf with
ghostscript.  We noted problems with pdf viewers but were unable to
resolve them.  We are including source text and postscript of the revised
paper.