decrypt my encrypted files

G

Guest

Some time ago I had to re-install my entire operating system due to some
error. I used a program called winternals to save all of my files to a backup
since my OS would not boot. Before this had happened I had some files that
where "Encrypted to secure content" (Right click
file/properties/General/Advanced/Encypt contents to secure data).

As my old OS had malfunctioned and I had wiped it off and re-installed my OS
on the same re-formatted computer, these files essentially where corrupted
since they where encrypted using the old machine and to the new OS they where
treated as normal files.

I need to find a way to decrypt these files that where encrypted using this
EFS system on the old OS.

I know my previous Usernames and Passwords to the old OS. But I don't know
if I made any encryption keys which is what a lot of the troubleshooting
websites talk about. I simply just right clicked the files and clicked
Properties - General - Advanced and checked the box labelled "Encrypt content
to secure data" and clicked the OK button.. and thatw as that.

Can anybody give me any help on this?

Regards,
Abhilash
 
M

Malke

Abhilash said:
Some time ago I had to re-install my entire operating system due to some
error. I used a program called winternals to save all of my files to a backup
since my OS would not boot. Before this had happened I had some files that
where "Encrypted to secure content" (Right click
file/properties/General/Advanced/Encypt contents to secure data).

As my old OS had malfunctioned and I had wiped it off and re-installed my OS
on the same re-formatted computer, these files essentially where corrupted
since they where encrypted using the old machine and to the new OS they where
treated as normal files.

I need to find a way to decrypt these files that where encrypted using this
EFS system on the old OS.

I know my previous Usernames and Passwords to the old OS. But I don't know
if I made any encryption keys which is what a lot of the troubleshooting
websites talk about. I simply just right clicked the files and clicked
Properties - General - Advanced and checked the box labelled "Encrypt content
to secure data" and clicked the OK button.. and thatw as that.

If you failed to backup your encryption keys or create a recovery agent,
the data is inaccessible forever. Next time read through all the
ramifications and cautions about using encryption before plunging ahead.

You can contact Elcomsoft and see if they think their program will help
you. If it won't, then I'm sorry but you can't get your data back.

http://www.elcomsoft.com/aefsdr.html - Encrypted files retrieval application

http://tinyurl.com/6l6xx - MS information about EFS (Encryption)
http://www3.telus.net/dandemar/encrypt.htm - encryption info
http://www.beginningtoseethelight.org/efsrecovery/ - more encryption info
To add a recovery agent for the local computer -
http://www.microsoft.com/resources/...docs/en-us/encrypt_to_add_recovery_agent.mspx
To change the recovery policy for the local computer -
http://www.microsoft.com/resources/.../proddocs/en-us/encrypt_to_change_policy.mspx
How to add an EFS recovery agent in Windows XP Professional -
http://support.microsoft.com/default.aspx?scid=kb;en-us;887414

Malke
 
V

VanguardLH

Abhilash said:
Some time ago I had to re-install my entire operating system due to
some
error. I used a program called winternals to save all of my files to
a backup
since my OS would not boot. Before this had happened I had some
files that
where "Encrypted to secure content" (Right click
file/properties/General/Advanced/Encypt contents to secure data).

As my old OS had malfunctioned and I had wiped it off and
re-installed my OS
on the same re-formatted computer, these files essentially where
corrupted
since they where encrypted using the old machine and to the new OS
they where
treated as normal files.

I need to find a way to decrypt these files that where encrypted
using this
EFS system on the old OS.

I know my previous Usernames and Passwords to the old OS. But I
don't know
if I made any encryption keys which is what a lot of the
troubleshooting
websites talk about. I simply just right clicked the files and
clicked
Properties - General - Advanced and checked the box labelled
"Encrypt content
to secure data" and clicked the OK button.. and thatw as that.

Can anybody give me any help on this?


If you use EFS, and since you are the admin of your own host, you are
expected to read ALL the help articles in the included help regarding
EFS. YOU are the admin. It is your responsibility to know the OS.
Doesn't matter that you don't unless you want to hire an admin that
says he knows the OS.

You are required to export the EFS certificate to safeguard it for
disaster recovery (which is what happened to you). You then import
that EFS certificate so the files that were encrypted using it can be
decrypted using that same certificate. You can also designate another
recovery agent to recreate the EFS cert for you, but you probably
didn't do that, either. So without a recovery agent and with no
exported EFS certificate, your encrypted files are unreadable.

There are other ramifications to using EFS. There are ways to crack
the login password for a Windows session. However, the methods used
to change the password can and usually will render EFS-protected files
as unreadable.

You might want to use TrueCrypt hereafter. Just don't forget the
password. There is no backdoor to EFS if you don't have the cert to
import or a recovery agent and there is no backdoor to TrueCrypt's
password encryption.
 
G

Guest

Thanks....

My files are decrypted by using AEFSDR software. Before this I recovered my
total Harddisk for encryption keys. I got some Encryption keys and using
AEFSDR my files are decrypted.

Abhilash
 
M

Malke

Abhilash said:
Thanks....

My files are decrypted by using AEFSDR software. Before this I recovered my
total Harddisk for encryption keys. I got some Encryption keys and using
AEFSDR my files are decrypted.

I'm very glad to hear that Elcomsoft were able to help you. I'm sure you
will be more careful with your encryption procedures now.

Thanks for taking the time to let me know.


Malke
 

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