Take the 2-minute tour ×
Ask Different is a question and answer site for power users of Apple hardware and software. It's 100% free, no registration required.

I use 1Password1 to store not only my own information, but also my sisters home Wi-Fi information.

Since she does not have a 1Password licence, I printed out the information for her to store in a safe place. Now, I was just thinking of using the printing dialog (under "Security Options...") to create a "password protected" PDF.

But what does that actually mean and how secure is it?

  • Does this encrypt the whole PDF?
  • What encryption is used?
  • Is it compatible with Windows and Ubuntu?

There does not2 seem to be a knowledge-base article on support.apple.com. The info dialog in Finder merely says that the PDF is "Password Encrypted".

enter image description here

share|improve this question

2 Answers 2

up vote 2 down vote accepted

The last Time I checked a 128 bit RC4 encryption of the whole document was used. Also, compatability should be vested.

Here's a screenshot of the output of GuaPDF: enter image description here

share|improve this answer
    
The download on the GuaPDF website was reported by Sophos AV to contain a virus "Slenfbot-E". Hence, I removed your link and cannot verify that 128-bit RC4 encryption is used. Do you mind creating a password protected PDF in Preview and checking it for yourself? –  gentmatt Jan 12 '13 at 12:50
    
So here's a screenshot. I encrypted the PDF with checking all check boxes in the Security Options. You have to decide if you trust the output of this application. –  cyphorious Jan 12 '13 at 17:21
    
Thanks for the update! I would always prefer first hand documentation by Apple about their software, but I'm willing trust this vendor for now ;) –  gentmatt Jan 12 '13 at 18:02

Another method, guaranteeing 256-bit AES encryption, is to use Disk Utility to create an encrypted disk image of a folder containing the PDF, or just a text file for that matter. One cannot create a disk image of a file - it must be a folder.

Steps:

  1. Create a folder, place file(s) to encrypt within
  2. Open Applications/Utilities/Disk Utility.app
  3. Menu item File > New > Disk Image from Folder
  4. Choose folder to encrypt
  5. Click the Image button
  6. Select .dmg save location, read-only and 256-bit AES Encryption:

    enter image description here

  7. Click the Save button, then enter a password of your choosing or use the 'Password Assistant' which can generate a password for you of several types and lengths. You are also able to store this password in your Keychain.

Naturally, the encrypted .dmg file can only be opened on a Macintosh.

This technique is handy for encrypting anything that can be put in a folder.

share|improve this answer
    
Thanks, I'm already aware of this nice and simple to use tool in Disk Utility. But I really want to secure the PDFs themselves because I cannot control if my sister's lax security practices will make her to simply copy the PDF from the encrypted disk image to somewhere else. –  gentmatt Jan 13 '13 at 7:39

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.