Signing PDF - multiple signatures with a single revision

Question

Hi,

To put it simply - I want to add multiple signatures on a PDF (using iText), without adding new revision for each.

I've read the following thread, and it makes much sense (since Bruno wrote the answer)

It is obvious, that if the document has 2 revisions, the first signature doesn't cover the second revision. However, is it possible (according to the PDF standard, and in iText) to have two signatures for the same revision? (I have set a certification level to CERTIFIED_FORM_FILLING_AND_ANNOTATIONS).

The point is that the document is created once and is not altered at all, except for adding the signatures. And since the signed PDFs will be sent to non-technical people, seeing the "the document has been changed" can trigger some 'disbelief' (due to lack of knowledge about PDF, which, alas, I can't expect of them). So, to put it again - it it possible to have 2 signatures in 1 revision, added at different times by different people.

Answer 1

I got a useful answer on the iText mailing list, which I'm going to share. Here, a guy nick-named mkl explains that with Adobe products this is down to a hen-and-egg problem.