Encrypt and password protect your pdfs
Ivan | Sun, 2009-07-26 08:54
The confidentiality of the materials you create for you client is very important. And, the bigger the account the bigger the stakes. Email is not a secure communication channel by default. Admins of every server that your email passes through can theoretically read your non-encrypted email.
Therefore, it doesn't hurt to add an extra layer of security when sending through important documents and presentations to your client. So, how to secure your documents without complicated additional software?

Securing your pdfs and jpegs is very easy. You can open them in Preview and resave them as pdf with the Encrypt option switched on.

Now, enter your password twice.

When your client or any other unintended recipient tries to open the pdf it will ask for a password.
Make sure to send the password in a separate email or other communication channel, such as IM or phone.
If you are saving from Adobe graphics or Apple's iWork applications you will have extra options to secure your pdf separately securing against copying or printing. Altough I think both of these options are pretty much useless, because they don't protect against retyping or a screen-shoot.
I attached a sample pdf that you can only open with the password: test.
| Attachment | Size |
|---|---|
| 4.07 KB |
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I had an issue with encrypted pdfs in the past, it was because I didn't know the pw. So I looked all around for a password couldn't find it and then started searching for pdf password openers.
The only solution was that if I used my mac to open the pdf it by passes the password portion of the pdf, but if I used my pc it stayed locked.
So if you happen to find yourself dealing with a locked pdf, use a mac to open it and you will be in open pdf heaven.
::Hire Insphyre Fire Performers::
I have trouble believing it.
Absolutely sure. I had issue with a pdf and didn't want to pay for a pdf hacker.
http://www.macosxhints.com/article.php?story=200512231728165
::Hire Insphyre Fire Performers::
I used to protect my documents all the time for legal purposes. Sometimes it's annoying when you forget the password and don't want to access the original raw file.
I also read a lot of pdfs from the internet and often get ones that are protected. To get around, I purchased a pdf cracker program. These programs are dirt cheap and they do the job in an instant.
So now I hardly protect anymore because anyone can buy these programs and crack the pdf in a matter of seconds.
As with Mac opening a protected pdf, I think I've done that many years ago. But with newer versions, I am quite certain you cannot do that anymore.
PDF's don't work on Macs!
http://stevefakeballmer.wordpress.com
I am not Steve Ballmer pretending not to be me!
obviously neither do you!
::Hire Insphyre Fire Performers::
Send me any encrypted PDF file and I'll send it back to you without password!
It's just too easy to remove it.
openSUSE
Linux for open minds
Yeah, nothing is totally secure. What do you use?
Don't have it with me at the moment. I'm in the office. Will send you the software name tonight.
Some things are totally secure! But not PDF files. At least I didn't find one I can't open/crack.
But I found some software which is totally impossible to crack it. That kind of software are specially encoded and the company paid a lot of money for such kind of encryption.
openSUSE
Linux for open minds
That is what I'm using now and it works nice.
It's available on Softpedia as well:
http://www.softpedia.com/get/Security/Decrypting-Decoding/PDF-Unlocker.shtml
But it's not free :) And it's works on Windows.
openSUSE
Linux for open minds
So, this means the file is not encrypted, just password protected?
I don't know. Send me some file and we will see.
openSUSE
Linux for open minds
Ah OK I see you have it attached. Will try to check that one.
openSUSE
Linux for open minds
Yes! You are right. It's locked. I can't crack it with PDF unlocker. Well done! :)
Didn't try with some other unlockers, but I guess it woudn't be so easy.
This is not simple protecting with password, this is encryption of the whole file. That's good :)
openSUSE
Linux for open minds
Thanks so much for taking the effort and try. I was feeling uneasy about this. :)
I have some untrustworthy clients, so what I do is save the file as a low resolution JPG and then save back to PDF. If the file is saved at about 150dpi then that's good enough for proofing but not good enough to print professionally.
I do use Acrobat's 'allow low resolution printing' option sometimes too. It baffles the casual user, and that's sometimes all that's needed.
Modern PDF password protection, including that used by Mac OS X / Preview as far as I know, uses 128 bit AES encryption and should be pretty safe as long as the password is strong. A combination of lowercase, uppercase, numbers and symbols, no dictionary words and at least 9 characters is ideal.
Leo Valen
leo (a) code.coop
Couple of related online tools: