University Park, Pa.—Publicly available cell-phone applications from application markets are releasing consumers' private information to online advertisers, according to a joint study by Intel Labs, Penn State and Duke University.
Researchers at the participating institutions have developed a realtime monitoring service called TaintDroid that precisely analyzes how private information is obtained and released by applications "downloaded" to consumer phones. TaintDroid is an extension to the Android mobile-phone platform that tracks the flow of sensitive data through third-party applications.
In a study of 30 popular applications, TaintDroid revealed that 15 send users' geographic location to remote advertisement servers. The study also found that seven of the 30 applications send a unique phone (hardware) identifier and, in some cases, the phone number and SIM card serial number to developers. In all, the researchers identified 68 instances of potentially misused private information by 20 applications.
"We were surprised by how many of the studied applications shared our information without our knowledge or consent," said William Enck, graduate student, computer science and engineering, Penn State. "Often, smartphone applications have obvious user interface changes when they use information like your physical location. These cases usually occur in response to the user pressing a button with clear implications. The cases we found were suspicious because there was no obvious way for the user to know what happened or why."
Smartphones offer a convenient way to download and install third-party applications. More than 200,000 applications are currently available in Apple's App Store and over 70,000 in Android's Market.
"Many of these applications access users' personal data such as location, phone information and usage history to enhance their experience," said Patrick McDaniel, associate professor, computer science and engineering, Penn State. "But users must trust that applications will only use their privacy-sensitive information in a desirable way."
Unfortunately, applications rarely provide privacy policies that clearly state how users' sensitive information will be used, and users have no way of knowing where applications send the information given to them.
The study was led by Jaeyeon Jung, research scientist at Intel Labs, and Enck. Their peer-reviewed report will be presented at the USENIX Symposium on Operating Systems Design and Implementation October 4-6, Vancouver, B.C., Canada. Co-authors on the paper are Peter Gilbert, graduate student, Duke; Landon Cox, assistant professor, Duke; Byung-Gon Chun, Intel Labs, Berkeley; Anmol Sheth, research scientist, Intel Labs, Seattle; and McDaniel.