Digitally signed with a certificate, or scribbled on (stamped) with a signature?
Digitally signed with a certificate
Well, the first issue is whether it can be changed at all. The signer (or form designer) decides that.
Clearly, any changes to a signed document must invalidate the signature, because the signature must reflect what the signer saw.
But we have something much worse.
1. The principle of signatures is that we can always go back to the earlier SIGNED version to see what the signer saw.
2. The principle of redaction is that the information must be absolutely and permanently removed.
These two aims are impossible to reconcile.
You could perhaps produce a completely unsigned document by printing to PDF, then going from there.
Thanks for the suggestion. Although I can print to PDF there is something preventing it from being recognised as a PDF - probably related to the digital signature.
Theoretically, I could bypass the whole issue by printing the PDF, blacking out the text manually, and then scannning the document to a new PDF. Unfortunately the document is over 100meg to start with and will exceed the memory available on the printer when scanning.
I suspect that in this scenario it can't be done without going back to the author/signer.
Nonetheless, thanks for the speedy response.
Can you explain "something preventing it from being recognised"? What is the symtpom you see when you try to print to PDF?
It would certainly be better to involve the author/signer in this, so they are aware of your needs and how their document preparation affects you. Printing to PDF, even if it works, can cause major loss of features and quality.
And re-scanning to PDF is catastrophic on quality and file size.
It is not a supported filetype.
When I save to PDF the following message is displayed:
%%[ ProductName: Distiller ]%%
This PostScript file was created from an encrypted PDF file.
Redistilling encrypted PDF is not permitted.
%%[ Flushing: rest of job (to end-of-file) will be ignored ]%%
%%[ Warning: PostScript error. No PDF file produced. ] %%
True, but these are the trade-offs one starts making. If it was feasible in this situation I would print, redact manually and scan.