Encrypt offline files
Offline files are copies of network files that are stored on your computer so that you can access them when you are not connected to the network or when the network folder with the files is not connected. Offline files are not encrypted unless you choose to do so. You might want to encrypt your offline files if they contain sensitive or confidential information and you want to make them more secure by restricting access to them. Encrypting your offline files provides you with an additional level of access protection that works independently of NTFS file system permissions. This can help safeguard your files in case your computer is ever lost or stolen.
You can encrypt your offline files by following these steps:
Open Offline Files by clicking the Start button , clicking Control Panel, clicking Network and Internet, and then clicking Offline Files.
Click the Encryption tab.
Click Encrypt to encrypt your offline files, and then click OK.
If you choose to encrypt your offline files, you encrypt only the offline files stored on your computer, and not the network versions of the files. You do not need to decrypt an encrypted file or folder stored on your computer before using it. This is done for you automatically.
In versions of Windows that do not include the Encrypting File System (EFS), the Encryption tab does not appear.