Possible to configure 7 to auto-wipe files?

[BitGroomer]

Hello folks,

I'm in the process of transitioning to Windows 7 and exploring the new capabilities that come with it. One feature I've long wondered about and considered potentially useful (but never actually ran into in the real world) is a OS/filesystem option which if enabled would cause the OS/filesystem to automatically perform appropriate wiping in response to events such as file deletion, the shrinking of files, shortening the name of files, completion of journaling steps, perhaps some other cases. Is it possible to configure Windows 7 to do that, be it via built-in existing capability or addon?

Note: I'm aware that there are various programs that can be user-invoked or scheduled to wipe specific files, wipe slack/freespace, that sort of thing. The feature I'm attempting to describe is one where wiping is more automated and integrated.

 

[logicearth]

Why would you need such a feature? And no Windows has nothing like that built into it. And don't see why it would need it either.

 

[Corazon]

The NTFS filesystem does have a journaling feature called the USN journal, which you can optionally enable for non-system partitions but which is always active on the Windows partition (and can't be turned off there).

There is no provision for wiping deleted files, and doing so would probably be rather inefficient and add a lot of disk accesses - deleting files would take as long as moving or copying them.

The only reason I can think of such a feature as being useful is privacy, and for that you might consider encrypting your system instead, for example with TrueCrypt.

 

[pincushion]

BCWipe has a Transparent Wiping option that does something similar - not sure if it does all that you require as I have not used it and I think there might be a performance hit. There is a forum so a search might give more information. BCWipe has quite a few other features too that might entice some like swapfile encryption and various wiping options.

 

[BitGroomer]

Thanks for the replies. Since I'm new here it is possibly worth mentioning that privacy and security are interests of mine, so I frequently think in those terms. FWIW, I am familiar with Truecrypt and other tools for creating encrypted drives and containers in which files can be stored. I particularly like encrypted file containers for storing sensitive records. The well known problem with that, of course, is that the OS and applications can effectively copy sensitive data from an encrypted store and write it to a less or not at all secured media. It's one thing if an app creates and leaves a temporary copy of such a file in a known directly where it can be subsequently selected for wiping. It is another thing for an app to make a temporary copy of a such a file and then delete it, leaving nothing for the user to select for wiping. Coupled with other issues such as storage devices internally implementing wear leveling and filesystems being in the best position to know what has to be over-written in order to purge sensitive data, this makes secure destruction something that requires some OS/device support.

That BCWipe Transparent Wiping capability is interesting and I'm looking into it. Ultimately, I will likely again utilize FDE as an outer layer of protection. However, even when using that I would welcome any improvements in the ability to overwrite destroy rather than simply delete file data.

 

[giblets]

I think this is an interesting question, BitGroomer.
It would be nice to encrypt the entire system, and have only a boot partition unencrypted. I don't think that's an option in Windows 7(but I'm no windows expert for sure), but if I understand what you're looking for then nothing on the drive would be unencrypted except the necessary boot files.
This is possible to implement on a different OS as I have set up my laptop that way, I'm interested in seeing how to do that in Windows 7.

 

[logicearth]

It would be nice to encrypt the entire system, and have only a boot partition unencrypted. I don't think that's an option in Windows 7(but I'm no windows expert for sure),

*cough* Bitlocker. From all the way back in Windows Vista.

 

[giblets]

Hmmm... I think I'd have to upgrade for that option.

 

[pincushion]

I think this is an interesting question, BitGroomer.
It would be nice to encrypt the entire system, and have only a boot partition unencrypted. I don't think that's an option in Windows 7(but I'm no windows expert for sure), but if I understand what you're looking for then nothing on the drive would be unencrypted except the necessary boot files.
This is possible to implement on a different OS as I have set up my laptop that way, I'm interested in seeing how to do that in Windows 7.

Truecrypt has been mentioned which does this and is free. From my own experience just using the encryption of partitions and containers this software is very reliable but I have not gone the encrypt-system-partition route as this does have more potential problems than benefits for me personally. :huh:

 

[Corazon]

Truecrypt has proven extremely safe and efficient for me, I use it on both my desktop and laptop for full system encryption. It's very well-written software and has never given me the slightest issue. (I donated to them too)

There are a few gotchas, mind you: If you boot from your Windows DVD, startup repair won't see any OS obviously. If you want to access it through the command prompt, you have to run Truecrypt in portable mode (say, from a USB stick) and mount the system partition before you can work with it.

It will also slightly complicate your backup strategy - if you image the running Windows system, the image ends up unencrypted. If you image the system offline (from a WinPE environment such as Macrium's rescue disc) you can image it encrypted but will have to image every sector, i.e. save a clone of the full partition into the image file.

Despite these issues, I think it's really worth it. Just takes a bit of planning ahead.

 

[BitGroomer]

...but if I understand what you're looking for then nothing on the drive would be unencrypted except the necessary boot files...

What I'm rethinking is the best approach to compartmentalizing/securing my own data as well as any client data I may process. I'd *like* to keep all of each entity's data in its own encrypted container with its own password... and not have to encrypt anything else. Practically speaking though, I still doubt it is possible to reliably prevent the OS and various applications from persisting unencrypted data to other media (such as the system partition). Encrypting that other media doesn't solve the leak problem, although it does to some extent mitigate it.

I don't know what you meant above. One approach to dealing with an OS and applications that leak data would be to put/run them in the encrypted containers along with the sensitive data. I need to learn more about VM platforms, but I suspect it might be possible to keep each person or entity's data compartmentalized and secured by having an encrypted virtual machine for each.

 

[BitGroomer]

Truecrypt... will also slightly complicate your backup strategy - if you image the running Windows system, the image ends up unencrypted.

Unless you backup to another Truecrypt volume, right?

 

[rraod]

If you want a secure delete function for any sensitive files, Xplorer2 (by Nicos Bozinis) from www.zabkat.com has a feature called "shred" files. This is an excellent explorer replacement (from $29.95) for all windows versions including windows 7 and supports both x86 and x64. The author claims that once a file is deleted with "shred" command, it is impossible to recover this file again. The "shred" function is as easy to use as a normal delete file function.

By the way, the freeware CCleaner has a feature to wipe the free space (including MFT area) securely (1, time, 3 times, 7 times and 35 times etc.) for securely cleaning the free space for those who are security conscious. This can be run whenever the system is free as it takes a long time... This can even securely clean a hard disk completely if necesssary.

 

[rraod]

The problem with encryption technologies built-in windows is that if your system gets corrupted and you need to reinstall the windows again, then it is impossible to recover the encrypted files. It happened to me once and I lost a good number of files in this way.

The windows encryption is based on the user id of a system and if you reinstall the system and create same username, the user id will be different from the earlier windows version and will fail to unencrypt the files.

One way of safeguarding the files would be to always copy the sensitive files on a separate external compact USB HDD and carry it with you always and never leave any of these files on the computer. This way you can isolate the files from the computer.

 

[BitGroomer]

@rraod: I think there are mechanisms to recover both EFS and Bitlocker encrypted files:

https://www.google.com/search?num=3...s+OR+bitlocker)++"recovery+agent"&btnG=Search

I know, way back when, I used EFS on XP boxes for awhile and went through the recovery agent preparation steps (which, IIRC, basically revolved around exporting and keeping safe a certificate) and I was was able to encrypt a file on one machine and decrypt it on another.

 

[rraod]

I had this problem on an XP machine when I have not followed these procedures to save the user credentials. It so happened that I was just experimenting these features and after some time totally forgotten about the encryption I have done. After more than six months, I have reinstalled my system to a fresh copy of XP and only later on I realised that I could not access these files which were on an external USB disk.... Lesson learned

 

[Corazon]

Truecrypt... will also slightly complicate your backup strategy - if you image the running Windows system, the image ends up unencrypted.

Unless you backup to another Truecrypt volume, right?

Yes, or you use the backup software's own encryption to protect the image file.

Another catch I forgot to mention earlier is that if you make a backup using this method and restore it later, the system encryption will be lost (since you're restoring an unencrypted image) and will have to be recreated with TrueCrypt after the restore.

 

[BitGroomer]

Well one theme common to some things in this thread (wiping, encrypting, backup/restores) is that they can be very unforgiving if we overlook something. Once upon a time I stored some personal files in an encrypted archive file and simply backed up that encrypted archive file. At some point that encrypted archive file became corrupted and unknowingly I was making backups of an archive file that I could never decrypt and access. A friend's home was once robbed, and they took her computer and disc carrying case. Fortunately, she kept her personal files encrypted and there was a copy of those encrypted files on a disc the burglar didn't get. Unfortunately, the one and only backup of her encryption keys was in the disc carrying case that was stolen.

I suspect we've all learned a lesson the hard way on more than one occasion. Hopefully we learn from that and in the long run gain more than we lost.

 

[pincushion]

Well one theme common to some things in this thread (wiping, encrypting, backup/restores) is that they can be very unforgiving if we overlook something. Once upon a time I stored some personal files in an encrypted archive file and simply backed up that encrypted archive file. At some point that encrypted archive file became corrupted and unknowingly I was making backups of an archive file that I could never decrypt and access. A friend's home was once robbed, and they took her computer and disc carrying case. Fortunately, she kept her personal files encrypted and there was a copy of those encrypted files on a disc the burglar didn't get. Unfortunately, the one and only backup of her encryption keys was in the disc carrying case that was stolen.

I suspect we've all learned a lesson the hard way on more than one occasion. Hopefully we learn from that and in the long run gain more than we lost.

One advantage of Truecrypt containers is that you can do as many copies as you think reasonable for backups on different HDDs and CDs/DVDs and you can backup the headers so there is less problems with corruption. Of course the problem of frequently updating and backing-up is always there. Having used Truecrypt for perhaps a decade I have never had a container that didn't open and the only problems I have ever had is with duff CDs and so using the best is advisable. The problem of having a sufficiently secure but memorable password still remains however but it is not impossible to do.

 

[Corazon]

Best thing you can do: put a really awesome password together, then study and learn it like your name or address or phone# or social security. Use it. Use it again. Keep using it.
The day will come where you won't forget it for the rest of your life.

(Just be sure to include it in your testament and last will! LOL)