Need to digitally sign a PDF document multiple times, don't want to save after every one.

[jetescamilla]

Hello, I'm trying to digitically sign (with certificates) PDF document of my engineering plans.  Each Sheet has my Structural Engineering Seal and requires a signature on top of it.  To satisfy the Board of Engineering requirements this signature has to be validated.  I can not place a signature on one sheet and save again and again for 78 instances.  Also, the waiting process balloons and get's longer and longer as it's validating each signature that many more times.

I can't be the first to try and use digintal signatures on engineering plans, surely there is a solution to this. 

Thank you.

[margueritek]

Since each Digital Signature effectively signs the entire document, you are signing the same document 78 times just to get an image of the signature on each page. Unfortunately, the PDF specification does not allow multiple appearances for the Digital Signature Widget type (if it did, you could sign once and show the signature in 78 places), The only way around this, in PDF, is to make each sheet a separate, signed, document. Then collect all 78 sheets into a portfolio. The cover PDF (the one holding the portfolio) could then be signed (once) against a statement noting that the individual portfolio items are themselves signed.

[jetescamilla]

Thanks for the work around suggestion but that doesn't seem practical for the number of sheets we have in a full plan set incorporating all sheets.  That's a ton of individual opening, signing, closing, etc.  

[try67]

You only need to sign a file digitally once. It applies to the entire file as a whole. What you're doing makes sense (kind of) when signing printed paper, not for a digital document.

[jetescamilla]

Unfortunately engineering plans don't follow the same set of rules as "legal type" document.  Each sheet needs to be stamped and signed by the registered Profession Engineer stating that they have taken ownership of all drawing on each sheet.  

[try67]

You can add a "wet" signature to each page and then digitally sign the file once at the end of the process.

At any rate, what you're asking for is not technically possible. If you want to digitally sign each page then you need to add a unique Signature field for each page, sign each one separately and save the file after each signature. And yes, the file-size will balloon as a result.

[Test Screen Name]

No, no, no and again no. Your idea is not just an abuse of the whole idea of digital signatures, it also just won't work. The file will get exponentially slower and slower and, long before you hit 78 signatures, will crash and be unusable. I know why you want it, but you must think again.

[jetescamilla]

Appreciate the truthfulness.  It just appears that Adoble PDF has no way of doing what I'm asking.  Engineed drawing require a signature from the Engineer of Record on each plan sheet.  All states require this.  There's lot of  "old school" engineers who don't want to shift their ways with modern technology but it sure appears as if adoble isn't helping my case during the COVID time where we can't interact in the office.

[margueritek]

I feel your pain. Digital Signatures were introduced with Acrobat 4, in 2000. Changing the specification to satisfy your requirements (for instance: multiple signature appearances for a single signature) would introduce an incompatibility in all previous versions of Acrobat and Reader, 20 years worth.

I would like to make the case for signing individual sheets as single page PDFs, the collecting them into a portfolio: If a revision to a single sheet is required, you can just replace that sheet in the portfolio, all others remain signed with the original signing date. If a different Engineer certifies a new or revised sheet, that single sheet (with the new Engineer's signature) can be added to the portfolio. Signing 78 sheets at one time tells me you must be an outstanding Engineer, never needing a revision or change order. 😉

[Test Screen Name]

I think the terrible mistake was to give signatures an appearance on pages. This has causes so much pain and trouble - and also encouraged people to look on the page for appearances - a completely worthless thing to do, but easier than learning the right way... if only digital signatures had left pages unmarked, by now we would be using them effectively.

[try67]

Agreed. It should have remained a hidden feature, with a bar that appears at the top of the file saying it's signed and the signature itself only visible under the Signatures panel, separate from the actual page contents. Having them on the page also creates an issue when printing the file (with the visible signature), and then being able to modify it, or scan it as a new (unsigned) file, etc. And of course the layman still thinks it's signed, because they can see the signature, right there on the page!

[margueritek]

If you don't have some kind of visible signature, you can't tell if the document is signed. People don't usually look at the pop-out panels or the menu bar. Long ago Acrobat showed a valid signature with a green checkmark over the signature, but then the checkmark remained when the document was printed, and that didn't seem like a good idea. So the validation indication was moved to the signature panel, but the certificate information (name, date) is left in the document. This still isn't perfect.

A long time ago, HR asked that we sign a document with our digital signature... then print it and send the hard copy to them. Understanding of digital signatures still has a long way to go.

[try67]

There shouldn't be a visible representation on the printed copy, because that copy is not properly signed.

I did hear of a plugin that can convert a digital signature to a QR code when the file is printed, which allows the user to verify the signature, but I don't think that's quite good either, as someone could easily take that code, scan it, and put it on a new version of the file, pretending it is signed. I guess the code could lead you to a link with the actual signed digital file, instead... And yes, people will have to get used to not trusting "wet" signatures. Only digital ones should be trusted.

[margueritek]

If you want that, you are always welcome to sign with an invisible signature.

[try67]

> If you want that, you are always welcome to sign with an invisible signature.

I'm aware of that. I'm saying (as TSN does) that that should have been the only option.

The main reason it's not is probably because people think of a "signature" as something you see on the page itself, not some "virtual" property of the file.

[Test Screen Name]

"If you don't have some kind of visible signature, you can't tell if the document is signed." Yes, you can, by the panels etc. "People don't usually look at the pop-out panels or the menu bar." They should. They MUST. Training is necessary. The more I hear the more I am convinced there must be no mark on the page, and this should be forced upon everyone - but we can't put the genie back in the bottle.

[Test Screen Name]

To be clear, I really do mean that having no marks should be forced on everyone, especially those who protest the loudest, because they are clearly the ones who need this change. Won't happen of course.

[Thom Parker]

What you need is a stamp with your signature on it. You can stamp every page, then lock the document with a digital certificate. 

https://www.pdfscripting.com/public/PDF-Signature-Stamps.cfm