#filevault2

「少し前にMacBook Proが動作しなくなったので、自分で外しておいたSSDからデータを取りたいのですが」とお問い合せ。 (more…)

  I det her blog indlæg har jeg skrevet lidt om hvad du kan gøre hvis du gerne vil holde dine data for dig selv, passe godt på den, dele helt private ting på diverse cloud services. Det er ikke ment som en manual, men lidt gode råd og nogle – synes jeg…

Sometimes, when FileVault or FileVault2 are just enabled on the Mac (specially with Lion OS X 10.7.x or Mountain Lion OS X 10.8.x), you may see at the login screen a unknown user account named "update needed". Additionally, in the login preference pane you can't choice the "automatic login" option.

Well, the problem can be solved easily but it is time-consuming. Follow the steps below:

Log in into the Mac as administrator.

Backup the Mac with Time Machine (optional but recommended)

Launch System Preferences selecting System Preferences from the Apple menu.

Click the Security & Privacy preference pane.

Click the FileVault tab.

Unlock the pane clicking on the padlock (administrator password required)

Disable FileVault and wait (...about 3hrs with a 250GB no SSD HD)

Restart the Mac (optional but recommended)

Go again at the FileVault tab.

Enable FileVault and wait (...about 7hrs for me!!!)

Restart the Mac. The unknown user account will disappear. Now you can also choice the automatic login.

If you have a encrypted volume created by FileVault or FileVault2 and you are doing a clean installation of Mountain Lion OS X in Disk Utility, maybe you can receive a

"Disk Encryption Failed. Disk Encryption failed with the error: There is not enough free space in the Core Storage Logical Volume Group for this operation bla bla bla"

message when you try to delete the volume.

When you click the "OK" button, the volume is magically hidden so only the physical volume is shown.

Don't panic, exit from Disk Utility, open the terminal and digit:

diskutil cs list

It will show a list of CoreStorage (or rather encrypted) volumes. Well, copy the UUID characters of the Logical Volume and digit:

diskutil cs delete THECOPIEDUUID

Replace THECOPIEDUUID word with the UUID characters just copied. It will destroy the logical volume group and erase initialize and mount the disk.

I do not believe in cyber security, it is absolutely impossible to have a fool proof system these days. Sure, Internet companies can always (and they do) put a lot of money and time in ensuring that their systems are secure, but inevitably there will always be bugs.

The story is completely different when it comes to your personal computer. Most of us have loads of pictures, videos and other personal information on our machines. Most people will often store passwords, keep logs, financial information on their computers. Bad people are out there, and some of them are going to want your information. It's unlikely that the everyday Joe has super secret information on his computer, but since it is very simple to carry out, why not take a little effort and secure your computer?

In addition to the hackers and crackers out there, Windows users need to worry about the giga loads of malware and adware that is available for Windows machines. If you install a good antivirus (in the software world, good and paid don't always rhyme!) chances are that you've safeguarded yourself from the first wave of attackers. Most of the malicious files, virus, root kits and trojans should be filtered out at first go. However, there is always the remote chance that the software you use has a zero day someone is sitting on. (Zero day's are bugs in software that are not made public, instead the hacker would rather sell this to the manufacturer of the software and make a decent sum of money). There are tons of bugs unknown to the original manufacturer, so to be on the safe side, you should update as often as possible. That way you get the best possible protection. Firewalls add another layer of protection. For Windows machines, a good combination to have is Avast + Comodos' firewall. Mac's usually do not need AV's, the built in firewall works superbly (Mac users, additionally you should go the advanced options and turn on Stealth mode, that makes you invisible to most attackers)

The stuff I'm talking about today though is encryption - 

Suppose that an extremely well written trojan breaks through and has access to your files, then what do you do? Screwed right? Well yes, but if you have encryption - no.

Encryption works in a very simple way, a fixed or adaptable algorithm is applied to all your files and this is converted into something that is not human readable or recognizable. Some very advanced algorithms are out there. You can rely of these to protect your files. Even if the attacker steals your files (mybankaccount.txt anyone?) the contents will make no sense to him at all. The decryption key will be with you, and you can always be assured that without the decryption key, there is no way the hacker or attacker will be able to crack it. (Well yes, poor algorithms, simple passwords, stuff like that can still happen)

Windows users can check out truecrypt, or the built in bitlocker (both are excellent). Bitlocker uses 128bit AES.

Mac users have a far fancier option, filevault2 (on Lion, filefault on anything before that). It uses AES-128-XTS, rest of the details are kept undisclosed. Cracking an encryption is just impossible with the usual analysis. Some very very advanced (and I do mean VERY advanced) attacks might be able to crack it, but in 99.99999 cases you'll be safe.

I have my personal computer - a MacBook Pro, encrypted end to end, and I recommended you should do this too.