TweetFollow Us on Twitter

Macintosh Data Encryption

Volume Number: 25
Issue Number: 04
Column Tag: Encryption

Macintosh Data Encryption

Protecting data at rest through disk encryption

by Rich Trouton

Introduction

One of the hot new items in recent years, in both government and corporate IT, has been laptop encryption. In large part, this is a technical solution to a human problem: data theft, loss or exposure. People lose laptops, thieves steal laptops because they're valuable, the kids find information that they're not supposed to on Mom's or Dad's computer and tell all their friends about it, and so on. Does everyone need encryption? Maybe not. My own personal yardstick is "Is there anything on this machine where I would have a problem with it being posted on the web, or tacked up on a public bulletin board?" If your own answer is "No", you probably don't need to encrypt anything. If your answer is "Yes", then you probably should.

How best to protect your data?

There are two main encryption strategies that are in use today on the Mac. The first is file and folder encryption and the second is whole disk encryption (WDE). Both have their pluses and minuses, especially with regards to data recovery. After all, encryption boils down to "scrambling your data so that other people can't read it." Normally, you try to make sure that all your data is intact; encryption strives to deliberately scramble what is saved to the hard drive. The trick with encrypting your data is that you want to scramble it in such a way that authorized people can unscramble it while no one else can.

File and folder encryption works pretty much like it sounds. It allows you to encrypt and decrypt selected files or folders. Tools that use this method make you choose what you want to encrypt and don't encrypt anything that's not selected for encryption. By and large, this is the method of data protection that Apple has chosen to support, and Apple has provided some great tools with Mac OS X for file and folder encryption. Another third-party encryption tool available for Mac OS X that uses file and folder encryption is TrueCrypt, which is an open-source project that supports Windows Vista/XP, Mac OS X, and Linux.

Whole disk encryption is also fairly self-descriptive. It encrypts an entire hard drive and everything on it. In this model, everything on that hard disk is encrypted and the only way to have it not be encrypted is to move it off of that drive. Because of this, WDE is the preferred encryption method for most corporate and government environments. Using this encryption strategy has been problematic for the Mac until fairly recently. In fact, until May 2008, there wasn't a whole disk encryption software solution available for the Mac that supported an encrypted boot drive. There are now a couple of software packages that support Intel-based Macs, but PowerPC-based Macs still don't have a WDE software package that allows you to boot from the encrypted drive. On the whole disk encryption side, the two main software packages available for the Intel Macs are PGP's Whole Disk Encryption and Checkpoint's Full Disk Encryption.

Mac OS X's built-in encryption solutions

As mentioned earlier, Apple has chosen to support the file and folder encryption method with its encryption tools. The main tools are encrypted disk images and FileVault in Mac OS X 10.3.x and higher.

Encrypted disk images are just like any other disk image you can create with Disk Utility, with the exception that they are password protected and that password is used to encrypt the disk image with AES-128 128 bit encryption when the disk image is first created. You can use them like any other disk image file. It may be copied to, or created on, network volumes or removable media including Zip drives, USB flash media or FireWire hard drives. A particularly nifty feature of encrypted disk images is that when mounting the disk image from a remote server, is that all disk image-related communication between the computer mounting the disk image and the server is protected with the same 128 bit encryption used to create the disk image.

FileVault takes the same encrypted disk image technology that Apple created for encrypted disk images and uses it to protect one particular folder: your account's home folder. How FileVault does this is by creating an encrypted disk image that's able to grow or shrink with the amount of data stored in your home folder, mounting that encrypted disk image when you log in and then un-mounting it when you log out. The user's home is encrypted using the same AES encryption that is available for encrypted disk images and the contents of the home folder are automatically encrypted and decrypted on the fly.

FileVault has some upsides and downsides. The biggest upsides are cost and ease of use. It's built-into Mac OS X (v 10.4 and higher), so you're getting it for the same price that you paid for OS X. Apple has also gone to a considerable amount of trouble to make sure that you hardly notice anything different about working from an account that's not encrypted from one that is encrypted. One other attractive feature of it is that, because only the home folder for a particular account is being encrypted, you're able to support the rest of the Mac like you always have without having to deal with the extra complications that encrypting the OS and your applications may bring.

The biggest downsides have to do with backups and with using network accounts where the password is managed from a server, instead of from your own Mac. In most cases, these accounts are being provided by an external directory service (like Apple's Open Directory or Microsoft's Active Directory).

With regards to backups, the problem is that FileVault, at its heart, uses a password-protected encrypted disk image. The backup software will not be able to unlock the disk image while you're logged out of your account and only backup the files you changed since the last backup operation, so it will try to copy the entire file. Worse yet, if you change the encrypted disk image while it's being backed up (for example, by logging in to the account) you can corrupt the backup, making it hard or impossible to restore your files if needed. That's one of the reasons why Time Machine on 10.5 only backs up a FileVault-encrypted home when the user logs out. The best solution I've found so far is to use Time Machine with an attached disk drive and log out of my account on a daily basis, but that may not be workable for everyone.

The problem with network accounts from an external directory service combined with FileVault is again that FileVault is using a password-protected disk image. The disk image only knows the password that's able to unlock it and doesn't check with any other sources, like the external directory service that actually manages your password. So it doesn't know that you forgot your password and had to call your company or school's help desk to get it reset, and it doesn't pick up the new password when IT resets your account's password on their end. All it knows is that the password that you put in to the login screen doesn't match the one that it needs to unlock the disk image. Fortunately, Apple has provided a way to reset the encrypted disk image's password via the FileVault Master Password, but this is a solution primarily built for dealing with OS X's own local accounts instead of network accounts. Leveraging the Master Password to help you recover network accounts that have FileVaulted local homes usually requires some work on the command line. The best solution here is both user education and IT training. The user education is training your users that they need to change their account's password from their FileVault-encrypted Mac. The IT training is in the various methods of recovering a FileVault-encrypted account's data and is for when your users forget their training, or just forget their password.

Third-party encryption solutions

There are a number of encryption solutions available from sources other than Apple. I'll only be covering the ones I'm most familiar with: TrueCrypt, PGP's Whole Disk Encryption and Checkpoint's Full Disk Encryption.

TrueCrypt on OS X offers both file and folder encryption and whole disk encryption for non-boot disks, but does not currently have all of the abilities that it does in its Windows version (which include whole disk encryption of boot disks, as well as offering the ability to create and run your PC from a hidden encrypted operating system). TrueCrypt is also free and offers the best cross-platform compatibility of the encryption systems I've looked at, as it supports Windows, Mac OS X and Linux. If you need to work cross-platform and keep your encryption solution the same, TrueCrypt is a pretty good solution.

From an enterprise IT standpoint, TrueCrypt has the disadvantage of not having a back door. If you don't have the password, you don't get in. Period.

You can download TrueCrypt from the TrueCrypt website at http://www.truecrypt.org/.

PGP's Whole Disk Encryption for Mac OS X offers file and folder encryption and whole disk encryption, though it only supports WDE for boot disks on Intel Macs. (On Power PC Macs, PGP still supports whole disk encryption, but you can't boot from any of the encrypted drives). PGP is very good at providing data scrambling and unscrambling without interfering with the user, which is pretty much what you want from an encryption product. You can even use your Mac normally while the initial encryption is running, as PGP is smart enough to know what disk sectors are already encrypted and which ones are not, allowing the system to work normally during the whole process. You will probably notice a very high loss of performance during the initial encryption process because the hard drive will be in really heavy usage (after all, PGP has to read and rewrite the entire disk surface).

From an enterprise IT standpoint, PGP has another advantage in that the company also provides server-based management tools to manage the encryption policies of your PGP-encrypted machines. Don't want your users to be able to turn off their encryption? PGP's management tools can provide that ability. Want to be able to show your auditors how many encrypted Macs you have, what's encrypted, and the last time they talked to the management server? PGP's management tools can provide that too. Your user forgot their password for unlocking PGP's encryption? PGP's management tools can provide a one-time password that acts as a recovery key which you can give to the user to unlock their encryption when they've forgotten their own PGP password, even if the user is off the network and frantically calling you just prior to that important presentation that they're giving 3000 miles away from the home office.

The main downside to PGP is that Boot Camp does not currently work in combination with an PGP-encrypted boot drive. If you need to run Windows on your PGP-encrypted Mac, I suggest using software like Paralllels or VMWare.

You can download an evaluation copy of PGP from the PGP website at http://www.pgp.com/desktoptrial/index.htmldownloads/

Checkpoint's Full Disk Encryption for Mac OS X is similar to PGP's overall design when it comes to whole disk encryption for Macs, though Checkpoint's solution is for the Intel Macs only and does not support Power PC Macs. Like PGP, Checkpoint's encryption is pretty good at scrambling and unscrambling your data in a transparent fashion, and also allows the Mac to be used normally during the encryption process.

Where Checkpoint fell short in my testing has been in the area of enterprise IT management, with the biggest problem being the issue of recovery keys. Unlike PGP, which offers the option of having the recovery key be generated and managed by a management server, Checkpoint's recovery key is generated by the Checkpoint software on the Mac itself. The problem then is that the recovery key then needs to be copied off of the computer and stored somewhere else. The Checkpoint-generated recovery key also periodically updates (usually, this is triggered by the Mac changing its hostname or some other similar global variable) so you need to also make sure that the copy of the recovery key you have is the latest one or you may not be able to use the key to recover your encrypted data.

For more information about Checkpoint's Full Disk Encryption for Mac OS X, you can go to http://www.checkpoint.com/products/datasecurity/pc/index.html

Protect your encrypted data - Back up

Protecting your data with encryption is a great way to guard it, but does require you to remember yet another crucial password, and losing the key is like losing the combination to an unbreakable safe. What's the best way to protect your data against this? Backups, backups, backups. Make a regular backup of your encrypted data to somewhere you know is safe. As mentioned earlier, Time Machine can back up your FileVault-encrypted home folder when you log out and you can use other backup tools to back up your data once you've unlocked the encryption and logged in to your account. One consideration to keep in mind is that there's usually no point in encrypting the files on your Mac if you've got an un-encrypted copy of your files in a place where the backups can be compromised easily.

Conclusion

Encryption is an important method of protecting your data. As we've seen, most methods can be transparent to the user. Depending on your needs, the Macintosh platform offers several different styles of encryption. From the built-in, disk-imaged-based home-directory-only FileVault to several vendors offering driver-level full disk encryption, you can choose how bullet-proof you need the protection to be.


Rich Trouton is a Macintosh sysadmin with over ten years of experience, both in the enterprise space and in the small business space. He lives in Maryland and is currently providing Macintosh support for an unnamed government agency.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Remotix 3.1.4 - Access all your computer...
Remotix is a fast and powerful application to easily access multiple Macs (and PCs) from your own Mac. Features Complete Apple Screen Sharing support - including Mac OS X login, clipboard... Read more
DesktopLyrics 2.6.6 - Displays current i...
DesktopLyrics is an application that displays the lyrics of the song currently playing in "iTunes" right on your desktop. The lyrics for the song have to be set in iTunes; DesktopLyrics does nothing... Read more
VOX 2.5.1 - Music player that supports m...
VOX is a beautiful music player that supports many filetypes. The beauty is in its simplicity, yet behind the minimal exterior lies a powerful music player with a ton of features and support for all... Read more
NetNewsWire 4.0.0 - RSS and Atom news re...
NetNewsWire is the best way to keep up with the sites and authors you read most regularly. Let NetNewsWire pull down the latest articles, and read them in a distraction-free and Mac-like way. Native... Read more
MacUpdate Desktop 6.0.6 - Search and ins...
MacUpdate Desktop 6 brings seamless 1-click installs and version updates to your Mac. With a free MacUpdate account and MacUpdate Desktop 6, Mac users can now install almost any Mac app on macupdate.... Read more
ForkLift 2.6.5 - Powerful file manager:...
ForkLift is a powerful file manager and ferociously fast FTP client clothed in a clean and versatile UI that offers the combination of absolute simplicity and raw power expected from a well-executed... Read more
Drive Genius 4.1.0 - Powerful system uti...
Drive Genius 4 gives you faster performance from your Mac while also protecting it. The award-winning and improved DrivePulse feature alerts you to hard drive issues before they become major problems... Read more
OnyX 2.9.7 - Maintenance and optimizatio...
OnyX is a multifunctional utility for OS X. It allows you to verify the startup disk and the structure of its System files, to run miscellaneous tasks of system maintenance, to configure the hidden... Read more
DEVONthink Pro 2.8.5 - Knowledge base, i...
DEVONthink Pro is your essential assistant for today's world, where almost everything is digital. From shopping receipts to important research papers, your life often fills your hard drive in the... Read more
Backblaze 4.0.1.878 - Online backup serv...
Backblaze is an online backup service designed from the ground-up for the Mac.With unlimited storage available for $5 per month, as well as a free 15-day trial, peace of mind is within reach with... Read more

Auroch Digital is Bringing Back Games Wo...
| Read more »
Carbo - Handwriting in the Digital Age...
Carbo - Handwriting in the Digital Age 1.0 Device: iOS Universal Category: Productivity Price: $3.99, Version: 1.0 (iTunes) Description: | Read more »
Draggy Dead (Games)
Draggy Dead 1.1 Device: iOS Universal Category: Games Price: $.99, Version: 1.1 (iTunes) Description: Ditch your dead end job and take up a rewarding career in Grave Robbing today!Guide the recently deceased to a fun filled life of... | Read more »
Bad Dinos (Games)
Bad Dinos 1.0.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0.0 (iTunes) Description: | Read more »
The Apple Watch isn't Great as a Fi...
| Read more »
Show the World What You See With Stre.am...
Live broadcasting is getting popular on mobile devices, which is why you can now get Stre.am, by Infinite Takes. [Read more] | Read more »
PhotoTime's 2.1 Update Adds Apple W...
The latest PhotoTime update is adding even more functionality to the handy photo organizing app. Yep, including Apple Watch support. [Read more] | Read more »
Oh My Glob! Adventure Time Puzzle Quest...
Finn and Jake are taking over D3 Go!'s popular puzzle game series in the upcoming Adventure Time Puzzle Quest. [Read more] | Read more »
Earthcore: Shattered Elements - Tips, Tr...
At first glance, Earthcore: Shattered Elements seems like a rather simple card-battling game. Once you’re introduced to skills that will change quite a bit. Even more so once you start to acquire hero cards. But it’s not so complicated that we... | Read more »
Dungeon999F (Games)
Dungeon999F 1.33 Device: iOS Universal Category: Games Price: $.99, Version: 1.33 (iTunes) Description: "The game you must play at least once in your life!" "The game with potential of million downloads globally!" ...is what the... | Read more »

Price Scanner via MacPrices.net

OtterBox Maximizes Portability, Productivity...
From the kitchen recipe book to the boarsroom presentation, the OtterBox Agility Tablet System turns tablets into one of the most versatile pieces of handheld technology available. Available now, the... Read more
Launch of New Car App Gallery and Open Develo...
Automatic, a company on a mission to bring the power of the Internet into every car, has announced the launch of the Automatic App Gallery, an app store for nearly every car or truck on the road... Read more
Memorial Day Weekend Sale: 13-inch 1.6GHz Mac...
Best Buy has the new 13″ 1.6GHz/128GB MacBook Air on sale for $849 on their online store this weekend. Choose free shipping or free local store pickup (if available). Sale price for online orders... Read more
Memorial Day Weekend Sale: 27-inch 3.5GHz 5K...
Best Buy has the 27″ 3.5GHz 5K iMac on sale for $2099.99 this weekend. Choose free shipping or free local store pickup (if available). Sale price for online orders only, in-store prices may vary.... Read more
Sale! 16GB iPad mini 3 for $349, save $50
B&H Photo has the 16GB iPad mini 3 WiFi on sale for $349 including free shipping plus NY sales tax only. Their price is $50 off MSRP, and it’s the lowest price available for this model. Read more
Price drop on 2014 15-inch Retina MacBook Pro...
B&H Photo has dropped prices on 2014 15″ Retina MacBook Pros by $200. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.2GHz Retina MacBook Pro: $1799.99 save $200 - 15″ 2.5GHz... Read more
With a Mission to Make Mobile Free, Scratch W...
Scratch Wireless, claiming to be the world’s first truly free mobile service, has announced the availability of a new Scratch-enabled Android smartphone, the Coolpad Arise. The smartphone is equipped... Read more
First-Ever Titanium Alloy Curved iPhone 6 Scr...
One of the most common problems with mobile phones is damage to the screens. The slightest drop can cause a dreaded spider web of gashes and cracks in the glass panel surface that can cost $hundreds... Read more
Preorder new 12-inch MacBook, $10 off, save o...
Adorama has new 12″ Retina MacBooks available for preorder for $10 off MSRP including free shipping plus NY & NJ sales tax only. For a limited time, Adorama will include a free Apple USB-C to USB... Read more
Will iOS 9 Finally Bring Productivity Friendl...
Ah, the irony. From its original announcement in 2010, Apple has doggedly insisted that the iPad remain “simple,” thus arbitrarily limiting its considerable potential as a content creation and... Read more

Jobs Board

Project Manager / Business Analyst, WW *Appl...
…a senior project manager / business analyst to work within our Worldwide Apple Fulfillment Operations and the Business Process Re-engineering team. This role will work Read more
Visual Merchandise Manager %u2013 Accessories...
…to be part of an incredible team. Imagine what you could do here. At Apple , great ideas have a way of becoming reality very quickly. Our Accessories assortment makes Read more
*Apple* Solutions Consultant - Retail Sales...
**Job Summary** As an Apple Solutions Consultant (ASC) you are the link between our customers and our products. Your role is to drive the Apple business in a retail Read more
*Apple* Solutions Consultant - Retail Sales...
**Job Summary** The ASC is an Apple employee who serves as the Apple business manager and influencer in a hyper-business critical Reseller's store which delivers Read more
Technical Project Manager - *Apple* Pay - A...
**Job Summary** Apple Pay is seeking an experienced technical PM…manage the rollout of features to merchants for the Apple Pay platform in the US Within this role Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.