Encrypt Mac data with FileVault
You can use FileVault to encrypt the information on your Mac. FileVault encodes the data on your startup disk so that unauthorized users can’t access your information. See How does FileVault encryption work?
Note: If you have an iMac Pro or another model of Mac with an Apple T2 chip, the data on your drive is already encrypted automatically. However, turning on FileVault provides further protection by requiring your login password to decrypt your data.
To set up FileVault, you must be an administrator. When you turn on FileVault, you choose how you want to unlock your startup disk if you ever forget your password:
iCloud account and password: This choice is convenient if you have an iCloud account or plan to set one up—you don’t need to keep track of a separate recovery key.
Recovery key: The key is a string of letters and numbers that’s created for you—keep a copy of the key somewhere other than your encrypted startup disk. If you write the key down, be sure to exactly copy the letters and numbers shown. Then keep the key somewhere safe that you’ll remember—but not in the same physical location as your Mac, where it can be discovered. If your Mac is at a business or school, your institution can also set a recovery key to unlock it.
WARNING: Don’t forget your recovery key. If you turn on FileVault and then forget your login password and can’t reset it, and you also forget your recovery key, you won’t be able to log in, and your files and settings will be lost forever.
FileVault encryption can’t be used with some highly partitioned disk configurations, such as RAID disk sets.
Important: After you turn on FileVault and the encryption begins, you can’t turn off FileVault until the initial encryption is complete. Encryption can take a long time, depending on the amount of data stored on your computer, but you can continue to use your computer as you normally do. After the encryption process is complete, you can turn off FileVault. If you have an iMac Pro or another Mac with an Apple T2 chip, data on your drive is already encrypted automatically, so turning on FileVault won’t take the same amount of time.
On your Mac, choose Apple menu > System Preferences, click Security & Privacy, then click FileVault.
If the lock at the bottom left is locked , click it to unlock the preference pane.
Click Turn On FileVault.
You might be asked to enter your password.
Choose how to unlock your disk and reset your login password if you forget it:
iCloud account: Click “Allow my iCloud account to unlock my disk” if you already have an account. Click “Set up my iCloud account to reset my password” if you don’t already have an iCloud account.
Recovery key: Click “Create a recovery key and do not use my iCloud account.” Write down the recovery key and keep it in a safe place.
If your Mac has additional users, their information is also encrypted. Users unlock the encrypted disk with their login password.
If there’s an Enable Users button, you must enter a user’s login password before they can unlock the encrypted disk. Click Enable Users, select a user, enter the login password, click OK, then click Continue.
Note: If you see an alert message that encryption has been paused, your Mac may have detected a problem that could keep the encryption from completing successfully. For example, if your Mac notebook is not plugged into an electrical outlet, the encryption process may pause until the power plug is connected.