According to:

http://www.sqlservercentral.com/columnists/bkelley/implementing_efs.asp


EFS only works on NTFS. Therefore, if you copy the file from the server where you've got encryption in place to a drive that isn't NTFS, you'll lose encryption. You may not be prompted that you will lose the encryption status of the file, so keep this in mind. If you have FAT or FAT32 drives in your environment.




>Hi,
>
>1. Thank for the reply. I have read the first article on SQL2k
>but need to confirm this issue, if we move the encrtyped file
>to a NON-NTFS volumns, is the encryption inside the file
>still present ?
>
>Please advise. Thank you
>
>
>
>>See if this can get you started:
>>
>>http://www.sqlservercentral.com/columnists/bkelley/implementing_efs.asp
>>
>>However, if you are working with SQLServer 2005, read this first:
>>
>>http://searchsqlserver.techtarget.com/tip/1,289483,sid87_gci1193101,00.html
>>
>>
>>
>>>Hi,
>>>
>>>If I want to provide more security for my SQL Server and want to
>>>use Window Server Encryption File System (EFS) for this protection.
>>>Is the following issues true,
>>>
>>>1. using EFS, the encrypted file will be encrypted. However, when it
>>>is copy to another NON-NTFS file system or OS, is the encryption still
>>>present in the file ? Is the file still encrypted.
>>>
>>>2. when EFS is in effect, other user cannot access or copy it. So, if
>>>my current database file which is encrypted using the EFS and my system
>>>have other backup software that is auto synchronising the database to
>>>another system. How can I ensure that the backup software will work without
>>>any problem ?
>>>
>>>3. Will EFS have any problem with antivirus or backup software ?
>>>
>>>4. If I need other system to access that encrypted file, how can I just let
>>>that system access it like opening it without any problem ? Please advise.
>>>
>>>Thank you