Decrypt Windows XP files encrypted with EFS

[akorbiel]

I need assistance to decrypt backed up data files (mostly image files such as jpg) that have been encrypted using windows XP utility, EFS Encryption, by following these steps:

1.) right-click on a file

2.) select properties

3.) click on "advanced" in the attributes section.

4.) select "Encrypt contents to secure data"

All files have been copied to an external disk, then the computer was reformatted and restored to factory condition. I found out that I no longer have access to these files (they appear green in windows explorer).

I am not able to decrypt my files.

How can I decrypt these files without the original key?

Thanks

[Sparda]

Windows XP will use an RSA 1024bit key by default. Providing it's implemented correctly, all hope is lost. As far as I am able to tell it has been implemented correctly. Your only real hope would be to recover the key for the disk using file recovery software.

[ansichild]

Encryption is meant to keep people out of your data. It works well.

[digip]

You could try this, but I don't see much hope:

http://www.elcomsoft.com/aefsdr.html

If you don't back up the certificate keys to the EFS then the data will be useless to you if you ever have to recover your system from scratch

http://www.nacs.uci.edu/security/New_Pages...forWindows.html

[Zimmer]

Just wait for end user level quantum crypto... then you can crack it... oh wait never mind ;)

[Brian Sierakowski]

Yep, same thing happened to me with one of my user accounts, had 1 encrypted account and my windows install blew up.

In the words of the famous poet slipknot, all hope is gone.

[barry99705]

Just ask beakmyn about not backing up your encryption key.... :P