When it comes to Microsoft’s certification exams, security is always a popular topic. You are expected to know how to use the different operating system features to increase local and network security. One such feature is the Encrypting File System or EFS.

Files that have been protected using EFS are encrypted at the file-system level. The benefit of this is that the files can only be opened by the user with the appropriate private key and certificate. Even if you were to reinstall the operating system, the files would still be inaccessible.

You can encrypt a file using the steps listed below. An important point to remember is that a file can not be both encrypted and compressed. If compression is enabled, it will be disable when encryption is enabled.

  1. Open My Computer and find the file you want to encrypt.
  2. Right click the file and select Properties.
  3. From the General tab, click the Advanced button.
  4. Select the Encrypt contents to secure data option.
  5. Click OK.
  6. Click OK to close the file’s properties dialog box.

Once you complete these steps, the contents of the file are encrypted. When you access the file, the contents are automatically decrypted. You can disable encryption on a file by completing the steps outlined above and removing the check beside the Encrypt contents to secure data option.

Another user can be given permission to open an encrypted file. Once you complete step 4, click the Details button. Use the Add button to configure which users have permission to transparently access the encrypted file.

So far I have only talked about encrypting files when you can encrypt folders as well. When encryption is configured at the folder level, any new files added to that folder are automatically encrypted.

[tags]efs,microsoft certification,exam,encrypting file system,encryption[/tags]