Applies to: Windows 8, Windows 8.1
A hardworking CEO decides to bring her work home with her, so she copies several confidential documents to a USB flash drive. When she pulls her car keys from her purse, the flash drive falls into the parking lot. What happens next depends on a choice the CEO made while back in the office:
Of course, the CEO should have enabled BitLocker, but how many CEOs do you know that are willing to wait half an hour while BitLocker encrypts their flash drive?
With Windows 8, BitLocker is up to 99 percent faster, depending on how many files are stored. If you have a new drive or just a few files on an existing device, Windows 8 can encrypt a new flash drive in less than a minute.
When you encrypt a drive with Windows Vista or Windows 7, BitLocker encrypts every bit of space on the drive, even if it’s not in use. Windows 8 introduces Used Disk Space Only encryption, which gives you the option to encrypt only space on the drive that is actively being used.
Try it for yourself. Grab a flash drive, any flash drive, and copy some files to it. Then, encrypt it both with and without Used Disk Space Only encryption, and compare how long each takes. If you haven’t used BitLocker before, this article will walk you through the process, step-by-step. At the end of the article, we’ll share our own test results with different flash drives and data.
First, encrypt an entire flash drive to see how long the process takes:
Get comfortable, because this could take 20-30 minutes. Once encrypting is complete, follow these steps to determine how long encryption took:
We’ll present our own results from several different tests at the end of this article.
By repeating the test using the same drive and data, we can eliminate variables that might impact our results. Follow these steps to reset your flash drive so we can perform the same test using Used Disk Space Only encryption:
With the flash drive returned to its original state, repeat the encryption process using Used Disk Space Only encryption:
Figure 1: Selecting Encrypt Used Disk Space Only can save more than an hour.
How do your results compare? Unless you filled the drive, encryption should have been much faster with the Used Disk Space Only option selected. The next section shows our own test results.
Everyone should try this test on their own; it’s fun and the results show dramatic improvements. This table shows our own times in a variety of different scenarios, all on a mid-range mobile PC.
|Flash drive||Full encryption time||Used Disk Space Only encryption time||Improvement|
|8 GB USB 2.0 drive with 1 MB of data||25 minutes, 26 seconds||0 minutes, 56 seconds||96% faster|
|8 GB USB 2.0 drive with 4 GB of data||28 minutes, 25 seconds||16 minutes, 28 seconds||42% faster|
|32 GB USB 3.0 drive with 1 MB of data||24 minutes, 30 seconds||0 minutes, 18 seconds||99% faster|
|32 GB USB 3.0 drive with 4 GB of data||26 minutes, 50 seconds||5 minutes, 48 seconds||78% faster|
Convenience and security are inseparable. The easier a security feature is to use, the more users will take advantage of it. By making BitLocker encryption faster, we hope more people will use it, and ultimately, everyone’s confidential data will stay secret. Note, however, that you should only use the Used Disk Space Only encryption option if confidential data has never been stored on the drive in the past. If the drive has previously had confidential files on it that were deleted, you should still encrypt the entire drive to prevent an attacker from recovering data from the now unused parts of the drive.
You can use Group Policy to require BitLocker encryption for removable flash drives by enabling the Computer Configuration\Policies\Administrative Templates\Windows Components\BitLocker Drive Encryption\Removable Data Drives\Deny Write Access To Removable Drives Not Protected By BitLocker policy. That policy works for Windows 7, too, but many users became frustrated waiting 20-30 minutes for BitLocker in Windows 7 to encrypt their flash drive. With Windows 8 and Used Disk Space Only encryption, the waiting time for new flash drives is less than a minute, providing security without inconveniencing users.
BitLocker in Windows 8 includes several other improvements, too:
Are you interested in learning more about BitLocker? Read Work Smart: Protecting Data with Windows 8 BitLocker.