Controlling Attachments

[Former Community Member]

I have a employment approval form which gets passed around, and different stages has to approve the action. They also attach files to the PDF document such as Position Description and so on. As each stage is signed, I make the part they completed read only. What I cannot figure out is how to make the attachments readable, but not replacable. If I make the attachment button READONLY, nobody can see the attachments at all. If the button is not READONLY, anyone at any stage can delete or replace a file attachment that was placed there by anyone else.

Because they are digitally certifying the process, this vulnerability is bothering me.

Anyone have any advice or ideas on what I should do?

Thanks in advance,

John Sarradet

[Former Community Member]

Hi John,



This is not a direct solution to what puzzles you, but I think it is a pretty fair approach.



The great thing with digital signatures and PDF, is that each time a document is signed, it keeps an internal versioning in the PDF file itself, i.e. the PDF stores a representation for each "signed state" of the document along with the "current state".



Best thing is, that if the user wants, they can always review these separate "signed states", and compare them to the current version.



To do that, the user right-clicks on each signature field, and selects "View Signed Version". Acrobat/Reader displays the exact state of the document, when this was signed by the individual signer.



This also applies for the attachments included in the PDF, either added or removed.



Take a look at this document, for example:

http://www.anodos.gr/misc/signatures.pdf



The document has been signed three times. Each time, the signer added an attachment. If you right-click on each signature, you will be able to see the three different states of the document:



1st sign-off: 1 attachment

2nd sign-off: 2 attachments

3rd sign-off: all 3 attachments



HTH,

Evangelos



PS: The "View Signed Version" command will not work from within the browser, you must open the document from the desktop.

[Former Community Member]

Thanks Evangelos.

I'm going to see if it will work in my project.



Regards,

John