Encryption versus File Vault.

apple_customer wrote:

Hello All,

I'm trying to secure my external hard drives against access to my data in case of theft but don't completely understand the process even after review online information on this topic.

I have read external hard drives can be encrypted and have also read that users should turn on File Vault to secure their drives and their datas. These are my questions:

A. What is the different between encryption and File Vault? Can both be applied to external hard drives and, if so, how do I do it?

File Vault is merely the "magic" which allows you to decrypt and log into that account. When first released, you had to decrypt with a password, then log into a user account. The encryption used for FileVault and encrypting an external drive is exactly the same.

All new Macs are encrypted already. Turning on FileVault just changes how the decryption keys are accessed.

B. How should I set up permission in 'Get Info'? Should deny access to everyone else ('everyone', 'staff', ...) and only grant access to myself? What is the best way to set this up so only I can access this data?

If you want only your user to have access while connected to your Mac, you would set yourself as the Owner r/w and delete the Staff group, and set everyone to no access. Except encryption, nothing will prevent someone from connecting the drive on another computer and overriding the permissions you set.

C. Is there anything else I should do to ensure my data won't be accessed by someone else in case my drives are stolen?

Encryption is all you need to do.

You can encrypt the drive as-is. While the risk is low, you should have a backup before you encrypt it in case something goes wrong.

A. For an external drive, you don't select "FileVault." FileVault only applies to the startup drive.

You would just encrypt the drive using Finder or Disk Utility. The drive must be using a GUID Partition Map in order to encrypt it. That's been around for quite a while, so yours likely are. If the Encrypt option does not appear in the contextual menu in Finder, then it does not have a GUID partition Map. The time it takes will be quite a long time for the 15TB drive. Certainly overnight at least.

B. If you have to copy it to another drive and reformat, encrypt it when you reformat, then copy the data back to the drive. Again, you won't select "FileVault" anywhere for an external drive.

You should back up all of your drives this way before trying to encrypt.

FileVault “IS” Whole Disk Encryption.

The entire disk is encrypted block by block.

You do not need additional encryption.