Uncovering Search Histories
Personalized services on the Internet need high levels of security
Source: “Private Information Disclosure from Web Searches (The Case of Google Web History)”
Claude Castelluccia et al.
Proceedings of the 10th Privacy Enhancing Technologies Symposium, July 21-23, 2010, Berlin, Germany
Results: Researchers successfully reconstructed the Web search histories of specific Google users by stealing the users’ credentials and impersonating them. They were able to identify about 65 percent of what the users had been searching for, and they could tell whether a user had searched for a particular term.
Why it matters: Personalized Web services can help make searches and other tasks faster, but the new research suggests that they could also be used to collect information about search histories that people might prefer to keep private. A single search on a public Wi-Fi network would be enough to expose a person’s search history to a potential attacker. Although Google has made changes to prevent search histories from being discovered, the researchers say that other search engines are likely to have similar vulnerabilities. They recommend that Web applications encrypt all searches and credentials.
Methods: Google encrypts sensitive information such as passwords, but it doesn’t encrypt the authentication credentials that it uses to identify particular users of its search service. By intercepting these credentials, the researchers were able to impersonate a given user. Then they performed automated test searches in the user’s name and pieced together the Web search history from the personalized recommendations that Google provided.
Next steps: The researchers plan to analyze other search engines for similar leaks. They also continue to track the progress at fixing the problems they found.