15 replies to this topic

[someone9987]

By any chance does CCleaner securely erase data with multiple overwritings or does it delete data normally?

[agumon]

normally...

[Caldor]

Hmm, this is an important feature request in my view.

Without this, this program isnt actually deleting any files. They are recoverable and indeed can be done so quite easily.

You will found various source code snippets around with routines to do this to various levels of standards compliance. A small UI option for no safe delete, and perhaps a choice of some of the leading delete standards around for the choice of when it is enabled.

Love the app though!

[TwistedMetal]

This is currently being worked on...

[Capman]

Caldor, on Sep 25 2005, 07:16 AM, said:

Without this, this program isnt actually deleting any files. They are recoverable and indeed can be done so quite easily.

<{POST_SNAPBACK}>

It was not (I believe), originally intended for CCleaner to delete files, it was intended to clean the hard drive and registry, thus making a computer work faster and more effectively. So what if files are recoverable.

I agree it will be nice to have a feature included, that securely erases files, but it is not at the top of my wish list.

[BadHead]

I would think that adding a data destruction component to CCleaner is all but essential - what is the point of the CCleaner Recycle Bin right menu option without data destruction?

[Caldor]

I agree BadHead. Proper deleting is an essential function. Regardless of it was originally intended or not, there is clear security implications with the use of this excellent bit of code and it is a natural consequence to expect proper security with actually destroying the data instead of leaving it to exist within the file system.

[Glenn]

I have to agree with CaPMan ... nice to have but not a priority.

I've used another cleaner with integrated shredder and it wasn't that useful:

1. It slowed things down (several minutes per GB per overwrite pass).
2. It only shredded files it was deleting. Anything that was deleted otherwise (including temp files for some app's) was untouched.

Note that a single pass on magnetic media should block recovery software but not serious efforts such as magnetic force scanning.

If you want assured destruction of data, I think you want a dedicated shredder to clear all deleted files on your hard drive using multiple overwrites.

Also, you want an app that can handle other media, e.g., flash memory stick (single pass only), diskettes, CD-RW's, etc.

[BigD]

You are all correct. I choose to use CCleaner because of its ease and speed. I use it to keep the computer lean and fast.

For privacy use a free space shredder such as Zdelete, (not free but pretty good value ), to clean out and wipe all the free space. Tip - start it when you are going out for the day, proper data destruction takes time!!!

[Andavari]

BigD, on Oct 14 2005, 03:17 AM, said:

For privacy use a free space shredder such as Zdelete, (not free but pretty good value ), to clean out and wipe all the free space.

<{POST_SNAPBACK}>

SDelete from Sysinternals is freeware.

[Glenn]

I'm currently using Eraser 5.7 (freeware by Heidi Computers).

It can erase "unused space" (files which have only been deleted) using single or multiple overwrites.

It also adds "Erase" to various appropriate Right Click menus. This feature is convenient if you want to shred specific files but may not be secure if you have edited the files at some point (it'll overwrite the current clusters but earlier versions may be written to other parts of the drive or media).

Speaking of edits ... anyone using MS Office may want to download their RHD (Remove Hidden Data) Add-in. It clears comments, versions, etc. that may not be obvious depending on your view settings. I don't know if other apps have similar utilities ... ever notice that if you delete content from a PDF, the file size often doesn't get smaller until you use Save As instead of Save.

[englishman]

BigD, on Oct 14 2005, 08:17 AM, said:

You are all correct. I choose to use CCleaner because of its ease and speed. I use it to keep the computer lean and fast.

For privacy use a free space shredder such as Zdelete, (not free but pretty good value ), to clean out and wipe all the free space. Tip -  start it when you are going out for the day, proper data destruction takes time!!!

<{POST_SNAPBACK}>

Correct me if I'm wrong but I thought that the problem with relying on cleaning 'free space' for privacy was that deleted files which had been overwritten between 'free space' wipes, would not be affected by the next 'free space' wipe & hence were relatively easy to recover.

Rgds etc

[rridgely]

Wow, I saw this post and wondered what happened to englishmen's post count and sig. Its "Englishman" not "Englishmen".

[Glenn]

englishman, on Oct 15 2005, 09:36 AM, said:

Correct me if I'm wrong but I thought that the problem with relying on cleaning 'free space' for privacy was that deleted files which had been overwritten between 'free space' wipes, would not be affected by the next 'free space' wipe & hence were relatively easy to recover.

Rgds etc

<{POST_SNAPBACK}>

You're right ... the clusters would only have been overwritten once by the new file. Since that data should have some logical pattern, the prior pattern should be easier to discern using magnetic force scanning. But what are the odds that the old file was completely unfragmented and is exactly overwritten by the new file ... and remains "protected" by the new file through subsequent file operations, defragmentations and erasures?

Erasing specific files with multiple overwrites and then doing the same with freespace is probably best. But where do you stop? Some standards call for 3 or 7 passes. Peter Gutmann supposedly suggests 35 passes (I can't even begin to understand some parts of his technical papers on the subject).

One overwrite prevents software based recovery methods. Beyond that, who do you think is after you?

[BigD]

We have moved off the thread a bit.

We started out discussing whether CCleaner should destroy the data when it clears out tempory files, internet tracks and of course the recycle bin.

I would think that the first two categories will be written and re-written in the allocated space. A periodic wipe of free space should add a belt to the braces.

Sensitive files should be shredded and not put into the bin anyway.

So my vote stays the same - keep CCleaner lean and fast.

[jake]

rridgley, cool explanation...now i always wonder when i saw the fbi leaving someones house with a computer, thinking, i hope he erased all his files...but i guess just emptying the recycle bin doesn't cut it lol

Edited by jake, 07 November 2005 - 03:12 PM.