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.

 
AAPL
$109.41
Apple Inc.
+2.67
MSFT
$45.74
Microsoft Corpora
+0.58
GOOG
$504.89
Google Inc.
+9.50

MacTech Search:
Community Search:

Software Updates via MacUpdate

BBEdit 11.0.2 - Powerful text and HTML e...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more
ExpanDrive 4.2.1 - Access cloud storage...
ExpanDrive builds cloud storage in every application, acts just like a USB drive plugged into your Mac. With ExpanDrive, you can securely access any remote file server directly from the Finder or... Read more
Adobe After Effects CC 2014 13.2 - Creat...
After Effects CC 2014 is available as part of Adobe Creative Cloud for as little as $19.99/month (or $9.99/month if you're a previous After Effects customer). After Effects CS6 is still available... Read more
Command-C 1.1.7 - Clipboard sharing tool...
Command-C is a revolutionary app which makes easy to share your clipboard between iOS and OS X using your local WiFi network, even if the app is not currently opened. Copy anything (text, pictures,... Read more
Tidy Up 4.0.2 - Find duplicate files and...
Tidy Up is a complete duplicate finder and disk-tidiness utility. With Tidy Up you can search for duplicate files and packages by the owner application, content, type, creator, extension, time... Read more
Typinator 6.3 - Speedy and reliable text...
Typinator turbo-charges your typing productivity. Type a little. Typinator does the rest. We've all faced projects that require repetitive typing tasks. With Typinator, you can store commonly used... Read more
GraphicConverter 9.5 - Graphics editor w...
GraphicConverter is an all-purpose image-editing program that can import 200 different graphic-based formats, edit the image, and export it to any of 80 available file formats. The high-end editing... Read more
Toast Titanium 12.0.1 - The ultimate med...
Toast Titanium goes way beyond the very basic burning in the Mac OS and iLife software, and sets the standard for burning CDs, DVDs, and now Blu-ray discs on the Mac. Create superior sounding audio... Read more
QuickBooks 2015 16.0.2.1422 R3 - Financi...
Save 20% on QuickBooks Pro for Mac today through this special discount link QuickBooks Pro 2013 helps you manage your business easily and efficiently. Organize your finances all in one place, track... Read more
Remotix 3.0.6 - 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

Latest Forum Discussions

See All

The Drive : Devil's Run (Games)
The Drive : Devil's Run 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: ON THE ROAD AGAIN! The Drive - Devil’s Run is classic point to point style racing game that pays homage to the classics... | Read more »
Procreate Pocket (Entertainment)
Procreate Pocket 1.01 Device: iOS iPhone Category: Entertainment Price: $2.99, Version: 1.01 (iTunes) Description: Create - anytime, anywhere. Made by the developers of the award-winning Procreate® for iPad®, Procreate Pocket™ allows... | Read more »
IRON FINGER - Mini Games Championship (...
IRON FINGER - Mini Games Championship 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Quick to play, easy to learn yet hard to master.. TAP, SWIPE & TILT your way through mini games that... | Read more »
Pentaction: Medieval (Games)
Pentaction: Medieval 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Pentaction: Medieval is a turn-based strategy board-game about chance and skill on the battlefield. Take control of your... | Read more »
Hipstify Review
Hipstify Review By Jennifer Allen on December 17th, 2014 Our Rating: :: COOL FILTERSUniversal App - Designed for iPhone and iPad Add filters, quotes, and fancy frames to your images, thanks to Hipstify.   | Read more »
Mighty Smighties Gets Evolve Cards and N...
Mighty Smighties Gets Evolve Cards and New Worlds Posted by Jessica Fisher on December 17th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Duckie Deck Card Wars Review
Duckie Deck Card Wars Review By Amy Solomon on December 17th, 2014 Our Rating: :: STYLISH GAME OF CARDSUniversal App - Designed for iPhone and iPad Duckie Deck Card Wars adapts the classic card game War for use on devices, complete... | Read more »
PDF Office Review
PDF Office Review By Jennifer Allen on December 17th, 2014 Our Rating: :: CONVENIENT PDF EDITINGiPad Only App - Designed for the iPad Want to create your own PDF files? Import them from elsewhere? Adapt a web page into a PDF? PDF... | Read more »
The Out There: Ω Edition Update will be...
The Out There: Ω Edition Update will be Releasing in 2015, Bringing Better Graphics and Additional Content Posted by Jessica Fisher on December 17th, 2014 [ permalink ] | Read more »
Pinball Planet Pro (Games)
Pinball Planet Pro 1.02 Device: iOS Universal Category: Games Price: $2.99, Version: 1.02 (iTunes) Description: - Our missionWe've always loved to play pinball games but we noticed most modern pinball games are simulators for the... | Read more »

Price Scanner via MacPrices.net

Holiday sales continue: MacBook Pros for up t...
 B&H Photo has new MacBook Pros on sale for up to $300 off MSRP as part of their Holiday pricing. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.2GHz Retina MacBook Pro: $1699... Read more
Google Search App For iOS Gets A Major Makeov...
Google has given iOS users an early Christmas present with a substantial update of it’s not-very-often-upgraded Google Search app. Google Search has been my go-to tool for Web searches since it was... Read more
ShopKeep Apple Pay And Chip Card Reader Avail...
ShopKeep, a cloud-based technology provider to more than 10,000 small business owners to manage retail shops and restaurants with iPads, has released its new Apple Pay and chip card reader. This... Read more
Holiday sale! 27-inch 5K iMac for $2299, save...
 B&H Photo has the 27″ 3.5GHz 5K iMac in stock today and on sale for $2299 including free shipping plus NY sales tax only. Their price is $200 off MSRP, and it’s the lowest price available for... Read more
Holiday Sale! 3.7GHz Quad Core Mac Pro availa...
 B&H Photo has the 3.7GHz Quad Core Mac Pro on sale for $2599 including free shipping plus NY sales tax only. Their price is $400 off MSRP, and it’s the lowest price for this model from any... Read more
iPhone 6 Number 3 Canadian Google Search Of 2...
CTVNews.ca reports that Apple’s iPhone 6 was the third highest-trending Google Canada search topic of 2014, exceeded only by Robin Williams largely after his death by suicide in August, and the FIFA... Read more
New iPad mini 3 Counter-Top & Wall Mount...
newMacgadgets has announced new secure all-acrylic displays for the iPad mini 3 (also works fine with the mini 2, last year’s iPad mini With Retina Display, and the original iPad mini). The new iPad... Read more
Holiday sales continue, MacBook Airs for up t...
B&H Photo has 2014 MacBook Airs on sale for up to $120 off MSRP, for a limited time, for the Thanksgiving/Christmas Holiday shopping season. Shipping is free, and B&H charges NY sales tax... Read more
B&H lowers price on 27-inch 3.2GHz iMac t...
B&H Photo has lowered their price on the 27″ 3.2GHz iMac, now on sale for $1629 including free shipping plus NY sales tax only. Their price is $170 off MSRP, and it’s the lowest price for this... Read more
15-inch 2.0GHz Retina MacBook Pro available f...
B&H Photo has lowered their price on leftover 2013 15″ 2.0GHz Retina MacBook Pros to $1499 including free shipping plus NY sales tax only. Their price is $500 off original MSRP. Read more

Jobs Board

*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
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
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.