I wish them luck with there new mailing list. The DB Techies Bits n Bytes News File. Caching By Browsers Creates A Threat To Surfers' Privacy. Web site operators may be able to monitor Internet users' surfing habits by making use of Web browser caches, and there may be no real solution to the problem, according to a new study from Princeton University. The new monitoring technique was revealed by Edward W. Felten, co-director of Princeton's Secure Internet Programming Laboratory.
Web browsers feature security features that prevent intruders from accessing a browser's cache.
Those security features remain tight, but Felten's discovery determines that intruders can scrutinize caches for files from certain Web sites. If the sought-after files are found, intruders can be sure that the browser user recently visited the Web site that the files originated from. The probing of files can be carried out by Java applets that determine how long browsers take to produce a page. Depending on how fast the page appears, the applet can determine if the page was stored in cache or taken from the Web. Ironically, anonymizer programs appear to make these cache probes easier to carry out, because non-cached pages become slightly slower to retrieve when these programs are used, says Felten.