---------- Forwarded message ----------
Date: Fri, 16 Jul 1993 18:13:45 -0500
From: Fritz Schwartz - X334 <SCHWARTZ@FAXON.COM>
Subject: Bellcore "time-stamping" of elec. files

This week I read a short but very interesting article that appeared in the
9 July, 1993 issue of Science (vol. 261, number 5118, pp. 162-163).  It
details the new practice, devised by Bell Communications Research (Bellcore
), of digital "time-stamping" ASCII files such as journal articles.  I will
not attempt to give you details of the practice here, but in effect it
permits a creator or publisher of an article (or even of a binary file such
as that representing an image) to create the equivalent of a check digit.
Naturally, this is not one character in length but rather a string.
However, the effect is the same, in that if anything in the text is cut,
added, or altered after that signature is created, re-computing the string
will not result in the same signature.  In effect, our community has for
the first time a means of authenticating or notarizing electronic documents
.  The article even has a photo-reproduction of such a "time-stamp", which
is now appearing in the Sunday edition of the New York Times!

Although I can think of possible applications to EDI, such as
authenticating internally imbedded text or images within ANSI X12 messages,
I immediately thought instead of the application in authenticating both
articles for document delivery and draft documents that might be
transmitted in preparation for publication in a monographic or serial
publications.  I must not have been alone among us in having worried over
the last year about willful or accidental corruption of such data streams,
as we have seen more and more references to electronic publishing.

Anyway, I recommend the article.  Probably some of you have seen a flurry
of comment about this on some "Listserv" or another, but it was news to me.

Fritz Schwartz
Manager, EDI and Standards
The Faxon Company
Westwood, MA
schwartz@faxon.com