Obtain and decrypt a personal recovery key with Profile Manager
If you have a Mac with FileVault enabled and enrolled in Profile Manager, you can obtain and decrypt the personal recovery key.
- In the Profile Manager  sidebar, click Devices. sidebar, click Devices.
- Select a Mac, then click the About tab. 
- Click the Security triangle, and download the encrypted personal recovery key. 
- Open the Terminal app, which is located in /Applications/Utilities/. 
- Enter the following, followed by a space, then drag the encrypted personal recovery key into the Terminal app. - security cms -D -i ~/Downloads/personal_recovery_key.dat- Note: The path to your file may be different. 
- Press the Return key.