OSX & FileVault Security Question...

fulmer

If your home directory is protected by FireVault, it's supposed to be safe, right... FireVault automatically unlocks your home directory when you log in, and locks it when you log out, right? Beyond what I mentioned above, I have no idea how FireVault works so that's why I'm asking. So here's my question:



If your computer is on, your logged in, all of a sudden the power goes out. The next time power is restored to the system, is your home directory relocked at boot, or is it safe even before that? What if someone removes the HD from your computer (after a power outage) and tries to access your home directory using another computer (using your disk as an external disk on their computer)? Is the "sparcefile" still locked? Or is it accessible?



I leave my computer on almost 24/7 and am curious about this. Home wiring here in Japan SUCKS! I blow the circuit breaker in my apt all the time.

dmband0026

You should be safe, because even if your power went out and someone grabbed your HD if they put it another machine the encryption would be in effect when the drive became powered again.

And it doesn't encrypt and decrypt your entire home folder when you log in and out, that would take huge amounts of time. It encrypts and decrypts "on the fly" so any file that is opened or removed/closed or added to your directory is encrypted or decrypted. So in short, no worries.



If you don't mind my asking, why do you need that much security anyway? Doin a little government work?

fulmer

na... no government work just curious!

I got bored at work and my mind started wandering

Quote:

Originally posted by DMBand0026

You should be safe, because even if your power went out and someone grabbed your HD if they put it another machine the encryption would be in effect when the drive became powered again.

And it doesn't encrypt and decrypt your entire home folder when you log in and out, that would take huge amounts of time. It encrypts and decrypts "on the fly" so any file that is opened or removed/closed or added to your directory is encrypted or decrypted. So in short, no worries.



If you don't mind my asking, why do you need that much security anyway? Doin a little government work?

brian green

A question about FileVault. Are all the bugs fixed? I use my PB a lot and many things I have on my laptop are sensitive in nature from a business standpoint. I used it a while back on a previous laptop and it always asked to reclaim disk space. Does it still do that? It that normal for FileVault? Are there any known issues I need to be aware of before turning it on? I just don't want to lose everything due to a glitch.

ichiban_jay

of course it still does it. Basically it'll reclaim space when you delete files from the encrypted sector. If the computer were to decrypt the empty space right after your delete command then the performance of the computer might slow down (then ppl would start complaining).



You can see what I mean by doing it yourself, first notice how much "free space" is on the computer according to the finder (say 17.0 gb free). Then when you delete a .8gb file and empty the trash can, the finder still says 17.0gb free. But, when you restart and have the computer clear up space the next time you check there will be 17.8gb free. Unencrypting the space basically.



Used it for about 5 months now on my powerbook, nothing bad happened so far.

brian green

Ichiban_jay, thank you for your reply. I'm happy to hear that you haven't had any problems.

jwink3101

i have heard some horro stories about FileVault. So, here is what i do using the security in FileVault.



The majority of what is on my computer the world can see. But, i do have about five spreadsheets keeping track of my bank account and credit card numbers. (plainly listed). What i did was i used disk utility to create a 500 meg sparsedisk and selected encryption. A 500 meg disk uses about a ~10 meg overhead regardless of what is in it but unlike a regular dmg, it doesn't use all 500 right away.



Now, when i need access to my spreadsheet, all i have to do is open the image and enter my password. (i make sure keychain saving is not selected). If you do accidentally save your password with keychain, just go into keychain access and delete it.



So now, i have all the security for my important files but no risk for the rest of them



I also back up my entire home directory to a single encrypted dmg on a portable hard drive (which i formatted to HFS+ tp hold the file)

brian green

My guess is that the horror stories you heard were from people before they installed the updates fixing the problem. At least I hope so. I use your idea of the encrypted DMG that is password protected without saving the password in keychain. The main reason I use FileVault is because I am in the military and have several evaluations and such on my laptop that are protected under the privacy act of 1974. I wouldn't want someone to get ahold of them through me. So I use FileVault. Being that I actually work with "Big Brother", I'm more concerned than if I were just someone that didn't want bank account numbers being accessible - though I fully understand the need to protect that information. Being that 98% of the government uses Windoze computers, I think just using a Mac in and of itself is a security measure. FileVault just adds peace of mind.

jwink3101

Brian,



Why not try using the sparseimages this way you don't also have wasted space. IT does make sense for you to use file vault. I am glad to hear that is has been fixed.



I may actually start using it now to save myself the time of created a .dmg of my homefold once a week to put on my portably hard drive (later placed in a fire-proof safe)

brian green

I'm not really concerned with wasted space. I have an 80GB HD in my 1.25 Ghz PB and have used less than half. Security is important to me, as it is to many readers and posters on this forum. I also use Crypt2 to encrypt items I deem to be of such import to make that necessary. The way I see it, I have the built in firewall enabled, I have all the file sharing preferences turned off, I have my home folder FileVaulted, an encrypted DMG for my sensitive work related items, and the items within that DMG are further encrypted with Crypt2. While these countermeasures will not ensure attainment of data if first-tier agencies choose to access it, it does prevent acquisition of useful data to nearly everyone else.



I believe most of us take security of data very seriously and have taken steps to ensure it is kept secure. While the measures I have taken are more than most take, I'm always interested in schemes others use to safeguard their data. The more active measures in place, the better prepared we are.

neutrino23

I've used FV since January without major incident.



To force FV to reclaim empty space just log out and log in. No need to restart.



I first installed FV when I wanted to send in my PB for repair at Apple. Not that I mistrust Apple so much but there is always the chance that the computer could get lost or stolen along the way.



Since then I've left it on as I travel a lot and there is always the chance that my PB could be stolen when on the road.



If you use iMovie you have to import movies to someplace outside your home folder. Encrypting is too slow to keep up with the camera.



A few times my desktop would fail to appear after a restart. One more restart would fix this. This hasn't happened in a while. Perhaps it was fixed in one of the updates.