How secure is File Vault & external encryption?

[Rockadile]

1. What kind of security is used for File Vault & external encryption?

2. If I enable file vault, when does it kick in? Before my user login? My user password is less secure for convenience at the moment.

3. I created a password for my external HDD that is ranked "excellent" and one notch before green bar is full. Theoretically, how long would brute force take?

 

[garirry]

1) AES-128 (128-bit)
2) It will begin encrypting files the moment you enable it. In order to log into a Filevault-protected account, you will be asked the password before the operating system is even loaded. Once you enter it, your data is unprotected until shutdown.
3) Depends what tool does the person use. Impossible to say for real, but if you have a password without repetitions, at least 8-10 characters long, with upper-case, lower-case, and other characters, it'll take too much time for anyone to be able to brute force (might theoretically take millions of years). Don't confuse password-protection and encryption though, make sure your HDD is encrypted, not just blocked by a password.

 

[Rockadile]

1) AES-128 (128-bit)
2) It will begin encrypting files the moment you enable it. In order to log into a Filevault-protected account, you will be asked the password before the operating system is even loaded. Once you enter it, your data is unprotected until shutdown.
3) Depends what tool does the person use. Impossible to say for real, but if you have a password without repetitions, at least 8-10 characters long, with upper-case, lower-case, and other characters, it'll take too much time for anyone to be able to brute force (might theoretically take millions of years). Don't confuse password-protection and encryption though, make sure your HDD is encrypted, not just blocked by a password.

2. I see, so File vault would kick in before the Apple logo screen? And only shutdown, not sleep wake up?

3. "Don't confuse password-protection and encryption though, make sure your HDD is encrypted, not just blocked by a password."

Not sure what you mean here. How would one create HDD password without encrypting?
I used disk utility to create a password for my external hard drive encryption.

 

[garirry]

2. I see, so File vault would kick in before the Apple logo screen? And only shutdown, not sleep wake up?

3. "Don't confuse password-protection and encryption though, make sure your HDD is encrypted, not just blocked by a password."

Not sure what you mean here. How would one create HDD password without encrypting?
I used disk utility to create a password for my external hard drive encryption.

2) What I meant is that in order to decrypt ALL information on the hard drive, you need to enter the password of any approved user at startup. When you are putting the computer to sleep and it wakes up, the data isn't encrypted, but you will still need the password to log in.
3) I just meant to say that you aren't just using a software to just prevent HDD access, the wording "I created a password for my external HDD" confused me. But I assume you did actually encrypt the drive so ignore what I said.

 

[ardchoille50]

1) AES-128 (128-bit)

I felt the need to add that this is the block length, File Vault 2 uses a 256-bit key for encryption.

 

[richard2]

3. I created a password for my external HDD that is ranked "excellent" and one notch before green bar is full. Theoretically, how long would brute force take?

It depends on the amount of computing power the attacker has. The creator of Diceware recommends that most people should use a passphrase comprised of either 6 random words or 5 random words with one random character inserted. (It's essential that the words and characters are chosen randomly.)

2. I see, so File vault would kick in before the Apple logo screen? And only shutdown, not sleep wake up?

Yes. If you want extra security, then lock your Mac's screen whenever you leave it.