Not all editions of Windows OS support Encrypting File System(EFS). See how to enable the Encrypt contents to secure data checkbox. If the Encrypt contents to secure data option is disabled, greyed out or unavailable in Windows 10/8. Another way to encrypt your data with EFS is by using the Command Prompt utility. Encrypt your file or folder with EFS, using Command Prompt. If you wish to decrypt a file or folder encrypted with EFS, follow the instructions you used for the encryption process, but this time uncheck Encrypt contents to secure data. Here’s what you can do to secure your NAS.
Unfortunately, some ransomware had infected the NAS and demanded payment to restore the data. Recently, some Synology owners discovered that all the files on their NAS system were encrypted.
