Boffins have come up with a new technique to protect users against more sophisticated forms of cybercrime. Indiana University School of Informatics and affiliated start-up RavenWhite have developed an "active cookie" as a countermeasure against online scams such as pharming and man-in-the-middle attacks.

Phishing involves trying to trick users into handing over security credentials to bogus websites, prompted through spam messages that pose as as emails from online banking or retail outlets. Pharming takes this attack one step further by attempting to intercept communication of personal data between a user and a genuine enterprise website by installing spyware, or by subverting DNS servers to redirect users to bogus websites. The technique is quite cunning because, in both cases, a prospective mark tells users they are at the correct website.

"There are no reliable commercial tools currently available to protect users from such attacks," said Jakobsson, associate professor of informatics and associate director of the IU Center for Applied Cybersecurity Research. "We believe that active cookies can provide such protection."

Active cookies are a "piece of cached and sandboxed executable code, such as a JavaScript object, that help authenticate an internet browser to a server", according to (paper) Active Cookies for Browser Authentication by the researchers on the subject. The technology is promoted as a shield against identity theft and cyber attacks that can protect against pharming attacks as well as techniques used to hijack Wi-Fi connections or modify consumer router settings.

The researchers admit, however, the technique has its limitations, such as limited persistence and a lack of support for roaming users. "And they do not offer security against strong attacks like active corruption of routers on the client-server path, as more holistic cryptographic solutions can."

Nonetheless, Indiana and RavenWhite think active cookies will be attractive to financial institutions - they complement existing techniques for user authentication, are easy to use, and don't have the potential security implications associated with browser plug-ins.

Jakobsson outlined his plans for active cookies and other research results on identity theft and its countermeasures when he moderated a panel discussion on Saturday (February 18) at the annual gathering of the American Association for the Advancement of Science in St Louis, Missouri. ®