Is this breakable? (file storing)

[æøå]

Lets say I have some documents which can make the difference between life and death, and it is very important that the files doesn't end up in wrong hands. (theoretically)

These files are now stored unprotected on my macbook. So my question is if this is a safe method to encrypt and store them:

1. Put the files in a folder on my macbook. Then use the Disk Utility software to create a password protected .dmg archive of the folder.

2. Put the .dmg archive in a new folder, and then create a new password protected .dmg archive, with a different password, of the folder containing the .dmg with the files in it.

3. Repeat step 2. couple of times with a new password each time.

4. Put the final .dmg archive (the one containing all the others) on a memory stick.

Is it possible to retrieve the files if, lets say CIA, get hold of the memory stick? The passwords are of course random letters and numbers etc. The files will then of course be lost for me, but will it also be lost for them?

And what if they obtain my macbook where the files were located before the steps above. Is it safe just to reformat my mac, then follow these steps http://docs.info.apple.com/article.html?path=DiskUtility/10.5/en/duh1011.html , or should I do more?

Also. If I, on a public computer, view the files. Can the files be traced or found on the computer even if I didn't copy the files to the computer, but only viewed them from the memory stick?


Hope this is the right subforum for my questions.

 

[mjsmke]

Its a pretty secure way of keeping files. Though im sure there are ways the CIA can get to them.

Viewing them on other computers is fine if you dont copy or save to that machine.

Why not keep the files protected on a small external drive? That way if you loose it, the average person wont know hoe to get to the files. Plus if the CIA conferscate your computer there wont be any *dodgy* files on there so they will asume your clean. Just keep the externa drive under the floorboards or something.

There is one other very secure way....but are these documents just text? if so how much?

 

[blevins321]

While I feel strange assisting with your money laundering activities, this info might help others. 4 levels of encryption would definitely do it. You might look into the open-source program TrueCrypt. You create an encrypted data bucket (think of it like a .dmg) of a specified size and you can enter the password into the program to mount the image. Truecrypt supports up to three levels of encryption using a single password (password decrypts key, key decrypts another key, which does the final key).

As far as erasing the hard drive, the 7-pass is plenty. 30 probably isn't even used by the NSA (and it takes a week-ish per drive).

 

[Hansr]

Viewing them on other computers is fine if you dont copy or save to that machine.

RAM nuff said.