Washington, August 26 : Carnegie Mellon University experts say that they have developed a low-cost system that can reduce the risk of eavesdropping on Internet communications.
The researchers say that their system, called Perspectives, can also offer protection against attacks related to a recently disclosed software flaw in the Domain Name System (DNS), the Internet phone book used to route messages between computers.
Assistant Professors David Andersen and Adrian Perrig, and Ph.D. student Dan Wendlandt at the university's School of Computer Science and College of Engineering have incorporated Perspectives into an extension for the popular Mozilla Firefox v3 browser, which can be downloaded free of charge at www.cs.cmu.edu/perspectives/firefox.html.
Perspectives employs a set of friendly sites that can aid in authenticating Web sites for financial services, online retailers, and other transactions requiring secure communications.
By independently querying the desired target site, these sites can check whether each is receiving the same authentication information, called a digital certificate, in response.
If one or more friendly sites report authentication information that is different than that received by the browser or other sites, a computer user would have reason to suspect that an attacker has compromised the connection.
The Perspectives system will be especially useful for the growing number of sites that do not use certificate authorities, and instead use less expensive "self-signed" certificates.
"When Firefox users click on a Web site that uses a self-signed certificate, they get a security error message that leaves many people bewildered," Andersen said.
However, once installed in the browser, Perspectives can automatically override the security error page without disturbing the user if the site appears legitimate.
The system also can detect if one of the certificate authorities may have been tricked into authenticating a bogus Web site, and warn the Firefox user that the site is suspicious.
"Perspectives provides an additional level of safety to browse the Internet. To the security conscious user, that is a significant comfort," Perrig said.
Andersen said that the increased use of wireless connections to the Internet had increased the risk of MitM attacks, which would occur when an attacker tricked a computer user into believing that the user had established a secure link with a target site.
In actuality, the computer user would be communicating with the attacker's computer, which could eavesdrop as it relayed communications between the user and the target site, the researcher added.
"With Perspectives, even if a client's ISP has fallen victim to the attack, the client will be able to detect that the public key received from the fake site is inconsistent with the results returned from the notaries," Wendlandt said.