Hi Gail,
I took a look at the PDF embedded digital signatures spec (URL below).
It looks good. I'd choose the larger (PKCS#7 X.509) certificate
format, because it's much more widely interoperable than the Raw
PDF signature format.
Could PDF digital signatures replace the use of TLS in IPPFax?
No - they would _complement_ the use of TLS in IPPFax?
In GSTN fax, the SENDER is implicitly verified and verifiable
to the RECEIVER (public GSTN switching fabric has logs of the
calls).
But a given document also has an AUTHOR (often not the SENDER)
and it's that AUTHOR who is verified with a PDF digital signature.
For example, a tachnical manager who is based in a San Francisco
office (the SENDER) sends a copy of the digitally signed contract
from a manager in Purchasing in the New York office (the AUTHOR)
to the RECEIVER. TLS verifies the SENDER. PDF DS verifies the
AUTHOR.
Cheers,
- Ira McDonald
-----Original Message-----
From: Gail Songer [mailto:gsonger at peerless.com]
Sent: Wednesday, August 07, 2002 2:25 PM
To: McDonald, Ira
Subject: PDF digital signatures and encryption
Hi Ira,
PDF has the ability to support digital signatures and data encryption as
part of the file format. I was reading through some of Adobes
documentation and it looks pretty cool but I was wondering if you would be
willing to supply a second opinion. You know a lot more about this than I
do.
Could IPPFax use this instead of TLS?
http://partners.adobe.com/asn/developer/acrosdk/docs/ppk_pdfspec.pdf
Gail