What happens to the un-encrypted copy of the file once it's encrypted?

[Ryan]

Hi,

It may seem like a silly question. But when you choose to encrypt a file with AxCrypt, I assume the process goes as follows: AxCrypt encrypts the file, and then shreds any temporaries/original copy? And when it is decrypted to be viewed it does a similar process where the file is decrypted, shredded and re-encrypted when finished. If I ran a file recovery software on my HD, surely I would quite easily see the un-encrypted version of the file that was shredded?

Or is it done in such a way where the original file cannot be found that easily. If you follow my thought path. I’ve used file recovery software in the past and I’m just wondering how well protected the files are after encrypting and de-crypting to view the content.

[SvanteSpectator]

Hello Ryan,

You are correct – we wipe plain-text files after they are no longer needed. This does not always mean that it’s impossible to recover, it depends on operating system, firmware and the hard drive among other things.

Normal file recovery software will probably succeed in recovering the *wiped* file, if done soon after the fact. But it’s still wiped.

[Mike]

Wow, this seems like a fatal flaw if I understand it correctly.  If I start a Microsoft Word document, and then save it and encrypt it, the old unencrypted version is recoverable?

 

[Ryan]

Yep Mike that’s my interpretation. Personally I keep any sensitive data on Hard Disks as opposed to SSD’s, as SSD’s are difficult to entirely clean unlike hard disks. Every 6 months or so I run Eraser which can fill the un-used parts of the disk with useless data essentially overwriting any “deleted” but still recoverable files with junk. I suppose the only way to be more secure would be to encrypt the drive as well as the files you’re using. With something like bitlocker so even when turned off no one can access and recover “Deleted” files. Still, “Shredding” is a bit misleading.

Svante, I noticed when using Axcrypt 1.0 back in the day I could quite easily recover files after shredding. Out of curiosity, has the algorithm been improved with 2.0? I haven’t attempted to recover any shredded files with 2.0 yet, I’m sure it’s still possible I’m just wondering if it’s been made any more difficult to do so?

Thanks for your reply!

[SvanteSpectator]

Hello Ryan,

I sincerely doubt that you really could recover files that were shredded with version 1. You might be able to seem to recover them, but it would be the overwritten version.

Also, you may have found temporary copies made by the application itself – we can’t control that. If Word for example makes a temporary copy, we can’t wipe that. That’s why we recommend to complement AxCrypt with EFS or Bitlocker or similar when using it for local PC security.

[Author]

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