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Known Participant
December 8, 2023
Question

Canva strips security from any locked PDF file - any solution

  • December 8, 2023
  • 3 replies
  • 6575 views

Background:

We supply PDF files to our client. Sometimes they like to make their own amends to these. The problems are obvious - our projects get re-appropriated for other use, the quality of the images, colours, and design is lost (images become mush, typographic formating lost), and we lose an editable master copy - so whenever we have to make amends which the client cannot, we have to trawl through their Canva edited file to find the amends they have made and apply them. Furthermore, the Canva version looks terrible which makes our work look bad - a business risk.

 

The problem:

I thought that providing the pdf with editing prohibited - no changes, no copying of text / images / no access for screen readers etc - all denied would fix this problem. However, when we tested this - bringing in this locked pdf into Canva it becomes fully editable.

 

Solution?

Apart from this being a massive security issue - where seemingly any copy within a locked pdf can be freely changed, is there another solution where the file can be locked down? canva will not import a password protected pdf, however that is not a solution as the files we supply need to be distributed.

 

Many thanks for help.

3 replies

Known Participant
December 8, 2023

The solution to the question I asked, is to convert all copy to outlines in the print production tool within Acrobat - the text cannot now be edited in any application other than at source - in InDesign.

MikelKlink
Participating Frequently
December 8, 2023
quote

The solution to the question I asked, is to convert all copy to outlines in the print production tool within Acrobat - the text cannot now be edited in any application other than at source - in InDesign.

 

That's overly optimistic.
But it indeed makes sure that edited versions will look even worse... 😉 

Known Participant
December 8, 2023

As mentioned earlier (or in a similar thread you started), anyone can take your PDF with the outlined text and run it through an OCR program (Acrobat, Abbyy FineReader, etc.), and end up with live text and graphics to edit. Depending on how long the document is, takes anywhere from 1-3 minutes.

 

Your client is looking for a way to circumvent using your services to make changes to the original design. In time, they'll find a way to do this, regardless of what you do to prevent it. The PDF file format is an open standard available to any company that wants to make tools to create, edit, render, process, or distribute PDFs.

 

From day one, PDF has never been a secure file format, and no one has yet invented a method to prevent a PDF from being edited or tampered with.  It's the nature of the file format itself. (Note, I'm a US delegate to the ISO committee that writes the PDF standard, ISO 32000.)

 

I like the suggestion above to put a digital signature in your file, maybe on the pasteboard. That can put a higher level of security into the PDF file that hopefully, Canva and other tools would respect. But then again, there's no guarantee about that.

 

Adobe's advertises that PDFs can be secured is pure BS. So many programs on the market can bypass that low-level security setting.

 

I think your client is sending you an indirect message: your not giving them everything that they need. Eventually, they'll find a way around you and maybe ditch your studio altogether.

 

As a fellow studio owner, I'd spend my time figuring out what my client needs and find a way to provide it to them. Maybe approach them with special pricing for your studio to make the changes for them within a set period of time, like 48 hour turnaround time. That keeps you in charge of the file, and the client realizes they need your skills.

 

Also tell them that when they muck around in a PDF on their own, they can damage the file and make it impossible for your studio to work with it in the future. Tell them in advance that the damage might require you to substantially rebuild or fix the mess they made...before continuing with the revamped design.

 


Yes, I've told them that. There are just a couple of 'problem people' in this organisation who try and save a couple of $ which is a false economy as when a serious update is required, we need to make those amends anyway. The people that have been doing this are junior level. We are not being sent any 'indirect messages'. There's no need to go into details on busines models etc, as our practice is sound - we are not getting ditched by anyone. The requirement in the original post was to add the element of prevention to these junior staffers. This is acheived. Case closed.

MikelKlink
Participating Frequently
December 8, 2023

First of all, PDF is a publicly specified file format, so anyone who can view it also can technically manipulate it. The mechanism you mention, the permissions, essentially only are hints to cooperative software. The PDF specification already mentions this, once the document has been opened and decrypted successfully, a PDF reader technically has access to the entire contents of the document. There is nothing inherent in PDF encryption that enforces the document permissions specified in the encryption dictionary.

 

What you can try, though, is digitally signing the PDFs before giving them to the client, and communicate that you accept only versions of the PDF with the signature still present and valid. 

Abambo
Community Expert
December 8, 2023

You should ask this in a Canva forum.

 

I do not know how you can protect a file from modification, if you can't password protect it.

ABAMBO | Hard- and Software Engineer | Photographer
Known Participant
December 8, 2023

I am asking here as the subject is about preserving the security of the Adobe PDF file.

 

I doub't the Canva community would promote and participate in the limitation of their own platform.

Abambo
Community Expert
December 8, 2023

There is no such thing as an Adobe PDF file. Even that Adobe developed the PDF file format, it is now an ISO standard, and Adobe is no more responsible for the format. Whatever Canva does, it is in Canva's interest to follow-up the standards.

ABAMBO | Hard- and Software Engineer | Photographer