Encryption can’t protect your data while you’re logged in
By Tony Bradley, PCWorldJun 21, 2013 3:30 am PDT
You carry a lot of data and sensitive information on your laptop, tablet, and smartphone. The standard method of protecting that information from prying eyes is to encrypt it, rendering the data inaccessible. But with most encryption software, that information becomes accessible the moment you log in to the device as a matter of convenience.
Think about what information that might be: names, postal and email addresses, and phone numbers for friends, family, clients, and business associates; calendar events indicating where you’ll be and when you’ll be there; personal photographs; and more. You might also have proprietary information about your company, clients, information that companies have entrusted you under the terms of non-disclosure agreements, and other sensitive information that should be secured.
Encryption basically scrambles the data so it’s nothing but unusable gibberish to anyone who isn’t authorized to access or view it.
And that’s great, but ask yourself this: How many steps must you go through to decrypt your data? Encryption is designed to protect data, but it should also be seamlessly accessible to the user—it should automatically decrypt, so you don’t have to jump through hoops to use your own encrypted data. And that means it’s not protected at all if someone finds your laptop, smartphone, or tablet in a state that doesn’t require a log-in password.
Using a Passcode
The Department of Justice and the National Security Administration—the same NSA that allegedly has omnipotent access to all data everywhere—have expressed frustration over iOS 6 and declared its encryption to be virtually impenetrable. There is a way to bypass it, but only Apple knows the magic trick, and there’s a massive backlog of requests from law enforcement.
There is also a general layer of encryption in iOS that functions purely as a means of remotely wiping the device running it. Rather than literally erasing all of the data—which would take a little time depending on how much data there is—this remote wipe tool simply resets the encryption key, instantly rendering the data useless. That’s handy, but it’s not foolproof.
iOS devices also have hardware-based encryption that protects your data, including your email and its attachments. That encryption, however, is tied to a passcode, meaning you must actually assign and use a passcode for your iOS device in order for your data to be protected.
The BitLocker encryption in Microsoft Windows works along the same lines. The TPM (Trusted Platform Module) chip provides a hardware-based element, and the user login provides the key to unlock the encryption and make the data available to the user.
All popular encryption tools lock data from unauthorized access, but are designed to unlock when a user successfully logs in. The data is then available as if it weren’t encrypted at all, and the user doesn’t have to take any additional steps to access or use the encrypted information.
But what if you’re already logged in?
Can you see the problem with this approach? This feature designed to make encryption more convenient renders the data protection impotent as long as you’re logged in.
Tripwire Director of Security Operations Andrew Storms explains, “If a thief catches your device in an unlocked state, they have a potential window of opportunity to access the data stored on that device.”
That “virtually impenetrable” iOS encryption relies on your device being locked with a passcode. When you set a passcode in iOS, you can choose whether the device should require the passcode immediately, or in one minute, five minutes, 15 minutes, or even an hour. An hour! If you choose that setting, you’re basically leaving your “encrypted” data exposed to potential compromise for 60 minutes.
The best way to secure the data on your mobile device is thus to configure the device to require a passcode after a relatively short period of nonuse. Set the time limit too short, and you’ll find yourself becoming irritated by repeatedly having to retype your passcode. Leave it unlocked for too long and you give a thief plenty of time to access all your supposedly encrypted data.
According to Tripwire CTO Dwayne Melancon, “In an enterprise environment, a lot of these complementary policies can be driven using group policies—for example, requiring screen locking, passwords upon waking, and setting short timeouts for automatic locking and automatic locking when the lid of a laptop is closed.”
While iOS and other mobile devices—as well as many other encryption tools—provide the ability to remotely lock or wipe the data from a device, that tool is useful only if you realize the device is gone. Every second your laptop, tablet, or smartphone remains unlocked while it’s out of your control is time that your encryption is not doing anything to protect your data.
Tripwire’s Storms points out that remote lock and wipe capabilities are no panacea: “On mobile devices, a clever thief will immediately disable all network access, so the device is unable to receive that remove lock or kill switch signal from corporate administrators.”
A better alternative to timed lockouts might be to have some sort of Bluetooth, NFC (near-field communication), or other close-proximity wireless device that pairs with your laptop, tablet, or smartphone. Keep this device on your person, and if you move too far away, your mobile device will automatically lock to prevent unauthorized access.