[pudolski]

hI,

(posted this in the wrong thread earlier)

When i transfer data from my comp to removable media by burning to CD or DVD or copying to SD card is it at all possible that others may have access to the underlying/overwritten data, which, i fear, may contain valuable personal information, that existed previously on the space that was copied from the hard drive.

I know it is possible to do this with a disk image but can it be done with normal burning/data copying?

I have been told this is not the case but haven't really been given a reason why. Could someone please explain and alleviate my concerns?

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If you copy data from your hard drive to another disk, CD or whatever, then delete the original data you copied from, it still remains at it's original location (on the hard disk) even after you've emptied the recycle bin. Windows simply 'hides' it from any file explorer listing and marks that area of the disk as 'available for new data'. But until that area is actually overwritten with new data, files can be recovered from it with any of several 'undelete' or 'file recovery' utilities. And even if that area is overwritten once or twice, some files can still be recovered partially.

It is generally considered that you need to overwrite 'free space' on the hard disk at least 35 times in succession to render the original data non-recoverable by all except forensic utilities as used by law enforcement agencies, but generally speaking over-writing 3 times is sufficient to frustrate attempts to recover old data by normal undelete methods. Even overwriting once is better than none at all, but parts of files could still be recovered with software.

If you want to overwrite your free space immediately for security reasons instead of waiting for several overwrites to occur during the normal course of PC usage (and not knowing which files are actually being overwritten in the process), you can download a free utility called 'Eraser' from here:
http://www.heidi.ie/eraser/

Use it either to erase (overwrite) files a preset number of times (instead of just deleting them), or use it to erase (overwrite) all the free space on the disk after checking that the Recycle bin is empty.

Edited by pip22, 06 December 2007 - 12:59 PM.

[pip22]

If you copy data from your hard drive to another disk, CD or whatever, then delete the original data you copied from, it still remains at it's original location (on the hard disk) even after you've emptied the recycle bin. Windows simply 'hides' it from any file explorer listing and marks that area of the disk as 'available for new data'. But until that area is actually overwritten with new data, files can be recovered from it with any of several 'undelete' or 'file recovery' utilities. And even if that area is overwritten once or twice, some files can still be recovered partially.

It is generally considered that you need to overwrite 'free space' on the hard disk at least 35 times in succession to render the original data non-recoverable by all except forensic utilities as used by law enforcement agencies, but generally speaking over-writing 3 times is sufficient to frustrate attempts to recover old data by normal undelete methods. Even overwriting once is better than none at all, but parts of files could still be recovered with software.

If you want to overwrite your free space immediately for security reasons instead of waiting for several overwrites to occur during the normal course of PC usage (and not knowing which files are actually being overwritten in the process), you can download a free utility called 'Eraser' from here:
http://www.heidi.ie/eraser/

Use it either to erase (overwrite) files a preset number of times (instead of just deleting them), or use it to erase (overwrite) all the free space on the disk after checking that the Recycle bin is empty.

Edited by pip22, 06 December 2007 - 12:59 PM.

[pudolski]

Thanks for the detailed reply, and im not trying to bump the thread but what i was asking was actually...

If i copy data to cd, dvd or flash drive, will the data that exists on a magnetic low level (i.e. overwritten data) transfer to the removable media by virtue that it still exists on the hard drive?

In other words when i make a data cd or copy files to an SD card is previous data from the hard drive (underlying layers) copied to the removable media as well as the existing data?

Does the copied data (as it exists on the removable storage) contain lower level recoverable layers?

In such case if someone copied my data from CD or drive to their computer would they be able to recover deleted personal information that existed below the CD data when it was on the hard drive?

Regards.

[dsenette]

In such case if someone copied my data from CD or drive to their computer would they be able to recover deleted personal information that existed below the CD data when it was on the hard drive?

like....if you copy fileA to a CD...but previously on your hard drive you had a completely unrelated fileB in the same location....could they use fileA to recover fileB from the removable media?

if that's your question then no...that's not possible...fileB (nor any of it's remaining info) was ever copied to the cd or flash drive

if you're asking if you've got fileA and fileB on a flash drive...and you delete fileB from the flash drive if they could recover fileB...then technically yes someone could recover that file because it originally existed on the media in question.....you cannot recover data that was never transfered to the media..