View Full Version : Best file shredder?

Jan 31, 2003, 07:05 PM
I've been looking at these types of programs more an more lately to safely deletey sensitive files from my computer. Which one is the best? Nearly all of these programs got mediocre reviews, at best, on versiontracker. Does this mean that none of them are worth downloading? Is there one that you like best?


Feb 2, 2003, 01:25 AM
Nothing will completely erase a file. Your best bet, depending on how serious you are, is to get something that overwrites the file(s) in question multiple times.

HDDs use electromegnetism to encode information. Simple erasure just deallocates the space, but leaves the information intact. By overwriting the file multiple times before deallocating the space, you make the electromagnetic signal fainter and fainter on the HDD. The 0s and 1s eventually become very faint or and hard to distinguish.

I use rm with the switch -P. This should be available on every OS X install: Overwrite regular files before deleting them. Files are overwritten three times, first with the byte pattern 0xff, then 0x00, and then 0xff again, before they are deleted.rm -P filename1...filename2..The hex 0s and Fs basically turn the questioned space into all 1s, 0s, then 1s again.

Feb 2, 2003, 06:25 AM
A proper DSE (Data Security Erase) uses six or 8 different patterns. Ithe first four or 0x00, 0xFF, 0x55, 0xAA, I don't remember what the others are.

It actually takes at least 6 overwrites before the data can't be gotten from the disk. However, if someone who can recover the data after a couple of overwrites wants your data, you probably have other problems. :rolleyes:

Feb 2, 2003, 09:06 AM
Yeah, I would be interested in something like this too. Coming from the windows world, there are many utilities out there that overwrite data to securely erase it. I used this one before I switched (it's for windows, but just an example) It overwrites files 35 times, as specified by the Department of Defense. I used it every time I deleted a file, just to be safe. It would be nice if there was a Mac version of this somewhere!

Federal Government strength eraser (http://www.heidi.ie/eraser/)

Feb 2, 2003, 09:12 AM
I was wondering about the same thing, as I've user Eraser and CyberScrub in Windows, and this would be a requirement for me should I make the move to Mac.

Here is a program I found. Notice that I don't have OS X, so I haven't used it and can't vouch for it...just a site I bookmarked a few days ago.

Shredit X (http://www.mireth.com/pub/sxme.html)

How secure is your trash? You shred your confidential paper documents, but how are you disposing of confidential electronic documents on your computer? You need ShredIt, the eDocument shredder. ShredIt provides an easy, permanent way to securely delete files and folders. Because throwing a file in the trash does not remove the file contents from the hard disk, just the file name, what you threw away can be recovered by someone else. Don't risk throwing confidential data in the trash - securely delete it with ShredIt X.

Feb 2, 2003, 11:11 AM
I have not used this yet, but this is another and only ten bucks.

TrashX (http://homepage.mac.com/northernSW/trashx.html)

Feb 2, 2003, 11:13 AM
if you have the dev tools installed (or just cc) you can download and compile the source for srm (Secure rm) which will overwrite the files before deleting them.


Feb 3, 2003, 04:32 PM
Originally posted by FattyMembrane
if you have the dev tools installed (or just cc) you can download and compile the source for srm (Secure rm) which will overwrite the files before deleting them.


Perfect! Thanks. This is not the type of utility that I was looking for, but it looks like it may even work better then a gui-based app.

Thanks again,

Feb 3, 2003, 04:48 PM
If you're worried enough about sensitive data to overwrite it 35 times, you may as well just get a solid state device for those files. there's a USB based HD that uses biometric thumbscans to allow access to it, and theoretically once a file is gone, it's gone. No EM signals to worry about...

edit: http://www.thumbdrive.com/

on the plus side, it's totally cool. i wish they would make one that's just a thumbscanner, instead of using passwords with OS X. i know 9 had support for alternative authentications, don't know about X...


Feb 3, 2003, 05:33 PM
Tell me...


I mean there is rarily stuff that I would need to delete that is that sensitive... I mean...

What the hell are you people doing with your computers?? :hugs iMac: