Encrypting File System (EFS) allows
you to encrypt data that is stored on drives on a file-by-file and
folder-by-folder basis. Data in an encrypted file cannot be read without
supplying the correct encryption key.
When you encrypt a file, Windows 8
automatically creates the private key that users need to access the
encrypted file and associates it with your Windows password. If you use a
strong password and don’t allow people physical access to your
computer, then your encrypted file is safe. When you look at an
encrypted file or folder, the only way you can tell that it is encrypted
is to examine its properties. If you created the file, you can access
the folder or file transparently and work with it as you normally would
because Windows automatically decrypts it for you.
When you encrypt a folder, all items in that
folder are encrypted. When you add items to the folder, they are also
encrypted. When you move an encrypted file in the file system, it
remains encrypted, but if you move an item to a different drive, the
file or folder is decrypted. Should you lose the user’s private key when
you reinstall the operating system or create a new user, you can use
the EFS recovery agent to decrypt your files. Administrators on
corporate networks can create a Group Policy that imports the recovery
certificate into the Active Directory and allows them to decrypt files
should the key be lost or should the user leave the company.
To encrypt a file or folder with EFS
1. Right-click the file or folder icon that you want to encrypt. Select the Properties command from the context menu.
2. On the General tab of the Properties dialog box , click the Advanced button to open the Advanced Attributes dialog box .
The General tab of a folder’s Properties dialog box
The Advanced Attributes dialog box
3. Select the Encrypt Contents To Secure Data check box. Tap or click OK.
The file or folder is encrypted to disk.
4. If you encrypt a file in an unencrypted folder, you will see a warning
indicating that using the file can make temporary copies of the file
available in an unencrypted form. Encrypt either the file or the folder
and then tap or click OK.
The Encryption Warning dialog box
Tip
Folder encryption offers more
protection than file encryption and should be preferred when possible.
Also, since the secret to encryption is the strength of your login
password, be sure to use a strong password and protect it from others.
