Signatures disappear when documents are merged.

[NUCONFH]

Dear PDF-XChange team,

We would like to merge at least two PDF documents that each contain two signatures (dual control principle).
together. However, each time we do this, the signatures in one of the documents
the signatures disappear. We have searched in all possible settings/menus for a solution without success.
whether your software has some kind of protection that prevents two separate documents with signatures from being merged?
signature can be merged?



However, if we merge the individual documents that have been signed with your software,
with the PDF24 software, all signatures are retained. As we would like to
continue to work with PDF-XChange and want to work around a workaround with two software solutions
solutions, we look forward to your help. Many thanks in advance.
Kind regards

[Daniel - PDF-XChange]

Hello, NUCONFH

The PDF Specification defines that a signature is a unique aspect tied to the signed document with clearly defined security practices in place. It is non-transferrable, and so we can not offer a method to merge signed files while retaining the certificate. If PDF24 does allow this, it is an indicator they do not take document security or the PDF Specification seriously. With that said, merging is not the appropriate method for this kind of process in any case, as it invalidates both signatures no matter how it is done.

If you need to keep two signed documents together, the appropriate process is to create a "PDF Portfolio" (File > new document > PDF Portfolio). This allows you to keep both files independent of one another in their original signed format, and instead "attaches" them to a "container" PDF file, for easy management and future access. This method prevents the process from damaging or altering either file, or breaking the permissions put in place by the signing party.

Please use PDF portfolios for this task going forward.

Kind regards,