Adobe Flash Player Private Browsing May Force Change in Fraud Fight

By Brian Prince  |  Posted 2010-04-12

Adobe Flash Player Private Browsing May Force Change in Fraud Fight

When the final version of Adobe Flash Player 10.1 hits desktops later this year, it will bring with it new functionality designed to allow users to automatically clear Flash cookies after a Web session. But while the feature may be lauded in the name of privacy, it may also force online banks to change how they fight fraud.

Flash cookies, also known as LSO (local shared objects), are used by many banks and e-commerce sites to identify legitimate users and block unauthorized or fraudulent access. In a report entitled, "Privacy Collides With Fraud Detection and Crumbles Flash Cookies," Gartner analyst Avivah Litan writes that the practice of using HTTP browser cookies for authentication gained steam roughly three years ago due to guidelines imposed by the Federal Financial Institutions Examination Council.

"Most banks responded by implementing stronger authentication that depended in large part on knowing that their online banking customer was logging in from a known PC," Litan wrote. "Upon entering a user ID to log into an online banking session, the bank Web server would check for the presence of this cookie...If the bank software could not find the cookie - for example because the user was logging in from a different PC - then the bank software would generally challenge the user with a series of questions that only the legitimate user could presumably answer."

But a growing desire for privacy led users to delete their browser cookies more often, meaning banks had to find something else to rely on, the report noted. Enter Flash LSOs, which are "basically hidden from casual users who aren't aware of them and don't know how to delete them."

Now that approach could be threatened as well, Litan told eWEEK. Flash Player 10.1 will respect the privacy settings configured in the user's browser so that LSO behavior automatically follows the browser's lead without any additional user interaction. All the major Web browsers, including Internet Explorer and Firefox, already have a private browsing mode where cookies are not stored by the browser.

"In my opinion, this is a big deal in the fraud world," she said. "Many banks, card issuers and online retailers rely in part on device identification to successfully detect fraud. And in many of these cases, the device identification they use is based on Flash local storage."

Options to Consider

Adding more user challenges in the form of security questions is bound to create its own set of problems in operating costs and customer experience, opined Ori Eisen, chief innovation officer at 41st Parameter.

"Imagine that a large ecomm player is used to less than one percent of their authentication logins being challenged and (ending-up) as a call center call," Eisen said. "What if this rate doubles...At one point the user experience will be unmanageable and very costly."

In her report, Litan suggested e-commerce and banking sites consider PC inspection software installed on a client PC or server-based, clientless program that can read information from the user's browser. Both approaches have their strengths and weaknesses: while PC inspection software can read information from the operating system registry, serial numbers off a hard drive or the Media Access Control ID from an Ethernet card, online banks loathe the idea of managing desktop software due to privacy and liability concerns, Litan wrote.

Clientless programs can use JavaScript launched from a service provider's login page to query the browser and gather dozens of parameters to identify a user's identity, Litan noted in her report. Vendors such as 41st Parameter and ThreatMetrix take this type of approach. However, clientless solutions "gather from the mobile devices is much cruder than what they can gather from desktop computers," she wrote.

"Certainly no method is perfect and we always recommend a layered security approach," she told eWEEK. "But cookies were proven unreliable years ago because so many users were deleting them which is why service providers turned to Flash local storage. And now Flash local storage will be proven unreliable and non-ubiquitous so many of the fraud detection systems will be thrown off guard."

Adobe Systems spokesperson Wiebke Lips said local storage capabilities in Flash Player and other similar Web technologies were designed to "enable rich Internet applications that help users transparently and securely save their information."

"Many businesses rely on Flash technology because it helps them provide rich functionality and compelling experiences that can reach more than 98 percent of users on the Web," Lips said. "However, Adobe has never promoted the use of local storage capabilities to store persistent, unique machine IDs without user consent. We also believe that as businesses choose fraud prevention approaches, their information retention policies need to be clearly communicated, so that users always have a choice over how their identifying information is stored."

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