Researchers at Georgia Tech have built a prototype that encrypts files before they are sent to the cloud for storage.
The so-called "CloudCapsule" system can be used with cloud storage services, such as Dropbox and Google Drive, for locking down files prior to their storage in the cloud and for accessing them without a proxy. The technology can be used for desktops, laptops, and mobile devices, but the researchers initially have built a prototype for just mobile devices -- specifically, iOS.
"We thought its greatest utility would be in the mobile space," given the explosion in BYOD, says Paul Royal, associate director of the Georgia Tech Information Security Center (GTISC), where the prototype was created. "This lets us combine the process isolation [feature] present in mobile OSes with a seamless and transparent way of encrypting data you want to place into the cloud."
It's the classic conundrum with the cloud: balancing utility with security. According to a new report published today by GTISC, corporate information stored in the cloud is typically secured solely with what the cloud storage provider offers. And encrypting data in the cloud via private-key encryption typically makes the cloud less useful, the report says.
In the desktop scenario, CloudCapsule basically uses a virtual machine instance that lets a user from the same machine go into encrypted mode and access encrypted files stored in the cloud. The operating system and malware have no "knowledge" of the data, according to GTISC, nor can the cloud provider read the files.
The mobile version, meanwhile, uses the process isolation feature in the mobile OS, GTISC's Royal says.
"CloudCapsule is an interesting approach and from the details available ... it seems specific to DHS, which may not be ideal for other users. A potential issue that enterprises might encounter is in the deployment," says Paige Leidig, senior vice president at CipherCloud, a cloud security firm.
Leidig says CloudCapsule would be difficult to scale compared with a single gateway model -- the approach CipherCloud takes -- because it's deployed on endpoints. "The other potential problem for the endpoint approach is key management -- if the user loses the keys, they would need to be revoked and replaced, which adds more complexity, especially for large enterprises with hundreds of thousands of users," Leidig said an email interview.
But searching encrypted information remains problematic. GTISC researchers also have been working on techniques for "searchable encryption" so users can more easily find their protected data and files in the cloud. "We are trying to design types of encryption that support ... performance requirements" of real-world users, GTISC's Royal says. "Consider a person who needs to encrypt data before it goes into the cloud, but would still like to do basic keyword searches over that data. That's something we've been working on at GTISC."
Striking a balance between securing the data and indexing or searching it is complicated, he says. "There are going to be fundamental tradeoffs between security and efficiency," he says. "In some cases, there's a desire not to introduce significant overhead, so, for example, in some cases, we are turning the problem on its head and asking a person who would use this in the real world what they consider acceptable performance."
[The cyberespionage gang out of China who recently hacked into media outlet networks is now using Dropbox and WordPress in its attacks rather than via traditional email phishing attacks and server compromise. See Dropbox, WordPress Used As Cloud Cover In New APT Attacks .]
Georgia Tech researchers also have built an email encryption prototype called "Very Good Privacy," a more user-friendly option than the existing Pretty Good Privacy email encryption tool. Very Good Privacy software sits atop the user interface and supports data encryption in texting/messaging apps such as email.
The tool intercepts and encrypts the text as it's typed in, before it gets to the email service. "Plain text never gets entered into an application," Royal says. But the look and feel of the process remains unchanged for the user, so it's transparent, he says.
Royal says VGP and PGP are actually complementary: unlike PGP, VGP does not use key exchange, for example.
The full Georgia Tech Emerging Cyber Threats Report for 2014 is available here (PDF) for download.
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