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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <html> <head> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii"> <meta name=Generator content="Microsoft Word 10 (filtered)"> <title>Message</title> <style>  </style> </head> <body lang=EN-US link=blue vlink=purple> <div class=Section1> Hi Rick,   Right now it’s spec’ed that the Stamp must be part of the image, and appear in one of three places, as a cover sheet, top of the first page or top of every page.   I like the idea of the shared image for all of the pages.   -----Original Message----- From: Rick Seeler [mailto:rseeler@adobe.com] Sent: Monday, February 03, 2003 2:00 PM To: Gail Songer Cc: ifx@pwg.org Subject: RE: IFX> Sender URI Stamp   <div> Gail, </div> <div>   </div> <div> Yes, I understand that the 'Document Information Dictionary' alone is not enough, also having the information in the image should be required.  I just wasn't sure where you were going with this. </div> <div>   </div> <div> As for you question; "maybe":  depending on what the digital signature is used for.  If I generated a digitally signatured PDF/is doc on my system and placed it on a web site, then someone transmitted that document using IPPFAX to someone else, my original signature should not be used as a "Fax transmission header".  This is an interesting situation.  Do we want to limit DSigs to just being used for "transmission headers":  I think not.  Therefore, we can either have two uses for them, or find another way to handle the "transmission header".  We could change the PDF/is spec to allow for more than one DSig (it is allowed in PDF) very easily (one sentence in section 3.3.16).  We would then have to specify that a certain DSig is for "transmission header" and all others are for "other purposes".  Each PDF/is document would only be able to have one of these "transmission header" DSigs.  We could specify this using the DSig's 'Name' or 'Reason' fields having a special value for the "transmission header".  Of course, using DSigs this way would move DSig support for the Consumer and Producer from 'Optional' to 'Required'.  Do we want this?  Using DSigs in this way, I believe, is a superior way to tag a fax transmission to adding some image of the information in the header of each page; but it has a cost.  One other benefit of this -- once the document is received, it can be printed out without the header tag information in the printout, if desired. </div> <div>   </div> <div> If we do not want to use DSigs this way, we are back to using an image of the header (are there other options?).  We could specify that this image header as part of the spec.  We could specify it as a shared image for all pages of the document.  This would allow the recipient to print the document without the header, if so desired.  But, by doing this, we make it easier for someone to replace the header during transmission.  Hmmmm. </div> <div>   </div> <div> Comments? </div> <div> -Rick </div> <blockquote style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt; margin-left:3.75pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'> -----Original Message----- From: owner-ifx@pwg.org [mailto:owner-ifx@pwg.org] On Behalf Of Gail Songer Sent: Monday, February 03, 2003 1:14 PM To: Rick Seeler Cc: ifx@pwg.org Subject: RE: IFX> Sender URI Stamp Importance: High Rick,   On a fax document, the date/time and ID of the sending machine are part of the transmitted image; added to the image by the sender.   In keeping with current fax, I would think that we still want this information as part of the image. So I guess I think that answer is “no, the information in the dictionary is not quite enough”. If the doc is printed and the soft copy discarded then this information is lost.   The digital signature does validate the data from the originating sender, but what if the receiving user decides to try to re-fax what he just got?  Do we replace the signature and the URI stamp?   Gail        -----Original Message----- From: Rick Seeler [mailto:rseeler@adobe.com] Sent: Monday, February 03, 2003 12:50 PM To: Gail Songer Cc: ifx@pwg.org Subject: RE: IFX> Sender URI Stamp   <div> Gail, </div> <div>   </div> <div> A digital Signature gives you a tamper-proof way to time-stamp a document, but besides that... </div> <div>   </div> <div> What about using the information in the "Document Information Dictionary" (See Table 9.2 in the PDF Reference 1.4)?  This dictionary is already part of the PDF/is spec. and should be all that is needed.  Of course, it's not tamper proof unless the document is also digitally signed. </div> <div>   </div> <div> Is this what you were looking for? </div> <div>   </div> <div> -Rick </div> <div>   </div> <blockquote style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt; margin-left:3.75pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'> -----Original Message----- From: owner-ifx@pwg.org [mailto:owner-ifx@pwg.org] On Behalf Of Gail Songer Sent: Monday, February 03, 2003 12:11 PM To: ifx@pwg.org Subject: IFX> Sender URI Stamp Hi,   It’s occurred to me that with PDF we have level of portability that we didn’t have before.  However the IFX spec requires that the sender add the URI of the sender:   The Sender MUST place the Sender’s URI, i.e., the value of the “sender-uri” attribute (see section 8.3), along with the date and time, in one of the following places, DEPENDING ON IMPLEMENTATION: 1.    On a cover page automatically generated by the Sender that is sent before the rest of the document. 2.    Merged with the first page of the document. 3.    At the top of every page of the sent Document. The Sender MAY include additional data (Sending User, Receiver identity, etc.).  As for regular FAX, it is RECOMMENDED that this information be represented as bit map data, so that it is more difficult for it to be modified before it gets to the Receiver.     My first thought was to add an optional field to the PDF that indicated where the Stamp was located.  If the doc was resent, then the second sender could replace the Stamp with its own stamp.  But if the doc was digitally signed then either the Signature would be lost or invalidated.   Anything thoughts on how we should handle this?    Gail </blockquote> </blockquote> </div> </body> </html>