# Can PDF files be edited/altered??



## Macaholic (Jan 7, 2003)

This is one of those "why is the sky blue" questions, but it is important for me to know this: can a PDF file be altered in any way once it has been created? How secure is the contents of a PDF file?


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## harzack86 (Jan 30, 2005)

It can be altered using Acrobat, unless the author locks it...

Some answers here:
http://www.adobe.com/products/acrobat/adobepdf.html


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## MacDaddy (Jul 16, 2001)

If you have acrobat pro you can. Not sure if it is a secure file (Password protected) if you can edit without a password, but if you have a file you want checked, send me a PM and I can check it out for you.


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## iMatt (Dec 3, 2004)

In addition to editing and altering with Acrobat Pro, you can annotate with Preview in 10.4.x. It's not like you can do anything subtle (it's all red circles and yellow stickies), but you did ask if they can be altered "in any way"...

Security settings and password protection have been part of Acrobat from the beginning. I don't know if they prevent annotation with Preview.


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## Macaholic (Jan 7, 2003)

Hey, thanks for the replies, guys! basically, I'm researching to counsel a medical practice in the use of PDFs generated by Mac OS X via the Print command. If they were to use this, it would have to be secure. My guess is that there's no way short off file vault for PDFs generated by OS X Print to be secure; ONLY via Acrobat. Correct?

Is there any general cross-platform security or password protection technology in existence??


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## Macaholic (Jan 7, 2003)

Thanks, iMatt. I forgot about annotations, which would be acceptable. It is the forging or malicious altering of PDF documents I am concerned about.


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## Gerbill (Jul 1, 2003)

You don't need Acrobat Pro - Acrobat Standard will do it too. 

So will Illustrator.

Of course, this is subject to the options set by the creator, as others have noted.

Also, these changes are so awkward to do that they are limited in practice to very minor edits, fixing typos, possibly replacing images with other images exactly the same size. 

If you want to get sneaky, there are OCR programs that will re-create the PDF document without any editing restrictions, saving it in any format you like.


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## CanadaRAM (Jul 24, 2005)

Macaholic said:


> Thanks, iMatt. I forgot about annotations, which would be acceptable. It is the forging or malicious altering of PDF documents I am concerned about.


If you use Acrobat instead of the print driver, you have options to set passwords and prohibit IIRC: Editing, Copying of text or images, Printing, and Notes

There are also some third party document workgroup-style tools that may be able to do much more in the way of automating security and workflow with PDFs. These will run into the $1000's but the business requirements may make it worth while.

Ideally, you would want some kind of plug in that created a checksum/digital signature with the PDF, and then verified that each time it was opened. Keep in mind that every additional security element will make the files less viewable by people who don't have the right software. 

The other thing -- Anything that can be displayed on a computer screen can by copied, altered and forged. All I have to do is take a screen shot of the 'secure' document, photoshop it, and re-distill it into a PDF for distribution. No, it wouldn't stand up to a side by side comparison with the original, but it very well may fool solmeone who is not familiar with your original documents.

Thanks
Trevor 
CanadaRAM.com


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## kloan (Feb 22, 2002)

What about "Encrypt PDF" under the print options? It doesn't lock it for editing, but it does give it password access only. There are other options there too, but I don't know what they do..


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## Macaholic (Jan 7, 2003)

Kloan?

_YOU ROCK, DUDE!!_ 











It's a Tiger-only feature and I'm not as familiar with the options in it. Tried it on a Tiger system. WORKS! THANKS!!


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## kloan (Feb 22, 2002)




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