Block PDF file conversion

So I'm revisiting the topic because I'm facing the same issue and I've found a solution other than the watermark (as this solution isn't feasible in my case).
Indeed, after working on the problem, I discovered that all you need to do is convert the PDF into JPG files before converting them back into a single PDF file.
Since the resulting PDF is encrypted as an image, websites like "ilovepdf" or "smallpdf" do not detect any text and cannot convert them. Even if they could, it would only display as a non-editable image in Word.
The downside is that this is a considerable waste of time when you have to do it for multiple documents or if the document in question has too many pages.
So I'm currently looking for a way to automate this procedure through software and/or a script.

Hello,
I am Breton, stubborn, and after much thought and experimentation, I may have found something.
For those who are picking up the problem midstream, it involves finding a way, a trick, to ensure the integrity of a PDF file. This file must be able to be opened, utilized, read, printed, but under no circumstances modified. The experiments mentioned above indicate that with the software "Smallpdf", it is possible to convert any PDF file into usable WORD or Excel files... whatever the security and protections. Once this conversion is done, any modification is possible, which is what I want to make, if not impossible, at least extremely difficult.
The trick I found does not prevent conversion, but the resulting WORD file or other is of such quality that it renders it nearly unusable.
- You create a WORD file,
- You "save as" to make it a PDF file, no need to secure it,
- You open this PDF file with the software "PDF Creator",
- In the PDF Creator software, you open the "Modify" section,
- You create a watermark "protected document", or something similar,
- You save this PDF file, which is now watermarked.

You can send this file to whoever you want. They can download it, open it, read it, utilize it, print it without any issues, but if someone tries to convert it to WORD using https://smallpdf.com/fr/pdf-en-word, for example, they get a file equipped with a watermark that cannot be removed. I have done numerous tests and found no way to do it. Furthermore, most images and pagination have disappeared.
Best regards,
nialpi

Hello,
Irony is a powerful engine for "the victim". Annoyed, I took a little time, but I found the solution to secure and encrypt a PDF file at 256, offering all options (reading, printing, downloading ...) except... converting to a Word file, which remains prohibited.
I add that I hadn't focused on this subject for 3 or 4 years. The evolution of technology is astonishing.
Thank you Raymond PENTIER
nialpi

Hello,
The solution is quite simple to prevent a PDF file from being converted to a Word file. Too simple; something's off. Let's start at the beginning.
- I have a Word file (2016) that I save with the .PDF extension.
This PDF file is publicly accessible; to secure it, I use a software: PDF Creator.
- I then open the .PDF file with PDF Creator. I use the "Security" function. I leave the "Access Password" function untouched.
In the "Permissions" function, I specify the options that interest me, in this case, all options except "modification" which I want to prohibit. I choose 256-bit encryption for the password.
So I end up with a .PDF file, seemingly secure. I can verify by using PDF Creator, or AC Reader, and try to convert this PDF file to Word. If I don't provide the password, it blocks. Okay?
I can rest easy: my .PDF file is safe from any conversion to a Word file.
Except that ...
I'm logical, I wanted to check. I went on the Internet, found: https://smallpdf.com/fr/pdf-en-word, which converted my 256-bit password-protected .PDF file by PDFCreator into a .doc file, editable, completely ignoring the password. I did the process 3 or 4 times, and it worked every single time. There are several apps that offer this function.
Well, alright, there are slight differences with the original Word file, very minor: since it's a free version, PDFCreator leaves its signature on some pages, the original Word watermark has disappeared, pagination leaves something to be desired. Just details.
In total: I have not found the right way to permanently prevent a .PDF file from being converted to a .doc file. I admit defeat, for now.
If anyone knows a method to prevent converting a .PDF file to a .doc file, I would be grateful.
Thank you
nialpi

Good evening,
I converted my PDF file to an image, I did it, but it doesn't suit the 122-page file that's filled with internal hyperlinks with bookmarks (multiple tables of contents). I'm losing everything. Moreover, I'm wondering if, despite everything, with OCR, it's not possible to convert these images back into Word...
I'll look into "read-only protection."
It's strange, though, this difficulty in being able to make a PDF file truly unbreakable for free.
Thank you, I’ll keep you updated, but if someone has a bright idea...
nialpi

Hello,
Last night and this morning, I went through a multitude of trials regarding "read-only".
I worked with the options, Microsoft, Word, AC Reader, etc.
Nothing works, the free app "smallpdf" laughs at all these so-called protected files. Whether for conversion to Word, Excel, Publisher... I tried all three.
At the same time, I tried to make it more difficult for the copier (contrariness)... Nothing.
I deduced one thing. The password protections required by the apps are encrypted. Since Smallpdf seems to bypass the passwords and all the barriers...
On the other hand, I’m looking for software that would encrypt ALL the words and images of a text. I think there’s a gap there, but does such software exist? At what price?
Thank you

Hello Nialpi

Try this method after installing
Libre Office (free) even if you have Microsoft Office

- In Libre Office, click on File -> Open and locate the .pdf file
- Go to File > “Export as PDF”
- Under the Security tab, click on the button “Set password”
- Enter the permission password and confirm the password below
- Click on “Ok
- Select the desired protections in the Print,
Modification, and Content areas
In “Modifications” set “Not allowed”

- Finally, click on the button “Export” to create the protected PDF file.

Good luck

Hello
I downloaded Libre Office and carefully followed the advice.
Unfortunately, no, the result is the same. There are, however, small differences in the final PDF file, but the modification is still possible when converting this PDF file to Word with "smallpdf."
Too bad, I believed it for a moment.
I am astonished by the ease with which "Smallpdf" operates.
Thank you for your advice,
nialpi

Hello,
Regarding a way to make a PDF file truly unmodifiable, meaning impossible to convert to WORD, regardless of the protections used: encryption, owner password, user password, paid or free software, I believe the answer lies in: https://www.01net.com/actualites/une-faille-irreparable-du-standard-pdf-permet-le-vol-de-tous-les-contenus-meme-chiffres-1778350.html .
I have just conducted around twenty tests over the past three days, using various methods to create PDF files, and each time the site: https://smallpdf.com/fr/pdf-en-word successfully converted the file, either to WORD or EXCEL ... easily, effortlessly. And this may not even be the most efficient site; I chose it randomly.
Is the deal sealed?
nialpi

Good evening,

It may not have been necessary to go through PDF Creator, which is really annoying with its prompts to upgrade for all the features.

- Saving the doc file as a pdf in Word.
- Opening the pdf in Foxit Reader
- Modifying the pdf by inserting a signature or text (the opacity is adjustable)
- Saving the pdf by printing it as a pdf. Going through printing as a pdf is imperative: if you just save it, everything that was just added can be easily removed.

Hello,
Reading your message, I understood that the goal was the same, whether by PDF Creator or by Foxit Reader. Since nothing withstands verification, I downloaded and installed Foxit from: https://www.foxitsoftware.com/fr/downloads/
- During installation, Foxit tried to modify a registry file, fortunately my antivirus was watching. Nonetheless, Foxit found a way to set itself as the default software for opening PDF files.
- I started Foxit and opened a PDF file. I only found the path "Protect" "Sign and Certify" "Place a Signature" to insert a watermark.
The watermark I could never validate because the "sign" box on the form remains stubbornly grayed out. I spent half an hour trying to find a solution.
I stopped the attempts. I’m not very clever.
So I’ll continue with PDF Creator.
Thank you for your message,
nialpi

Hello,
Thank you to Pierr10 for his very clear message. After reading it, I reopened "my" Foxit and compared it with the site you mentioned. I understand that I can't operate at my convenience because everything related to "stamps" is grayed out.
It’s possible that this is because I refused Foxit’s installation to affect my registry because my antivirus (paid Avast) raised a red flag with an alarm.
If that's the case, I'm ready to uninstall Foxit and then reinstall it properly.
nialpi

Good evening,
I have not had any success with Foxit. I uninstalled the software and then downloaded a new version. The result is the same, everything that requires a stamp is grayed out, so it's non-operational. I'm done here.
That's okay because with the free PDFCreator, I achieved my goal on the first try: inserting a watermark on a PDF file from WORD, a watermark that cannot be removed after conversion. So if someone wants to download the PDF file, they will have a small discreet watermark on every page; if they want to convert this file back to WORD, there will still be this watermark and a few other issues.
Thank you for all your advice,
Have a good evening,
nialpi

Hello,
Totally agree, Hoxy, wait 2 or 3 days, I'll send you a watermarked pdf file to convert to Word.
I'm on the move.
Thanks
nialpi

(re) Hello
I was able to free myself up much sooner than expected. Here is a PDF file of which I am the owner, which is open for viewing, reading, and downloading, but cannot be modified. Initially, it is a Word file, "saved as" a PDF, with no protection.
I then opened it with "PDF Creator" for free, watermarked it, and saved it. The conversion to Word is possible, but the watermark is (theoretically) unremovable; that is what I need to ensure. Furthermore, some images are missing in the images on pages 35 to 50, and the free PDF Creator software has left its mark at the bottom of all pages. For me, this is fine because I don't see anyone trying to claim it as their own.
https://www.nialpi.fr/434198278
Let me know if you manage to convert it to an editable Word file, please.
If you succeed, I have no further ideas to ensure the confidentiality of the file.
Thank you
nialpi

Good evening nialpi

I'm sorry to inform you that I managed to obtain the original Word file in less than 5 minutes.
Actually, I only worked on page 2 which I isolated using the Sam software (Split and merge).

I sent the page to Ilovepdf for conversion: https://www.ilovepdf.com/

I obtained a file with a easily selectable watermark; I was therefore able to remove it without any problem.

Here is the Word file with the watermark: https://www.cjoint.com/c/ILcutsPxOcK
and with the watermark removed: https://www.cjoint.com/c/ILcuuLxjtOK

I wasn't really surprised by the result. The watermark needs to be much bigger!
Like this: https://www.cjoint.com/c/ILcuxRSLlRK
When we request the conversion on Ilovepdf, it doesn't find any text!
We can obviously do something more discreet. The main thing is to really overlay the watermark onto the text.

• I would like to point out that when working with Foxit Reader (and probably Acrobat), there's no logo placed at the bottom of the page!
• I want to clarify that the watermark is well integrated into the PDF and cannot be removed.

I wasn't holding out too much hope. I thought someone would tear apart what I believed to be good, but so quickly, I'm stunned. Congratulations.
It all sounds great, but I'm left with the same problem I had 8 days ago: how to make a PDF file non-editable, or very difficult to modify? The possibility of inserting a watermark that's larger, very large? I don't quite understand that. I'll look into "ilovepdf."
I'm going to bed now, feeling down.
Thank you
nialpi

Hello
Thank you for your advice. I'm trying to open the provided link, and I'm getting:

I think I've understood your explanations about the watermark, but no view is opening.
Okay, I need to download the file, but where is it located?
Sorry for being such a newbie.
nialpi

Hello,
This thing is driving me crazy! Something is escaping me!
Every time I want to create the watermark, I end up at the view:

I can only add the watermark, I do get a watermark on pages 2 to 122, which looks like the one I get with PDF Creator, but nothing that resembles yours.
Something is escaping me, I say.
Good evening,
nialpi

Hello,
With: https://www.ilovepdf.com/fr
I then choose the "watermark" option.
nialpi