Mozilla this week announced improved user privacy in Firefox 86, with the introduction of a new feature aimed at preventing the tracking of users from site to site.
Called Total Cookie Protection and built into Enhanced Tracking Protection (ETP) Strict Mode, the new feature was designed to confine cookies to the websites that created them, and complements the Supercookie Protections that Mozilla introduced in Firefox 85 last month.
“Cookies, those well-known morsels of data that web browsers store on a website’s behalf, are a useful technology, but also a serious privacy vulnerability. That’s because the prevailing behavior of web browsers allows cookies to be shared between websites,” Mozilla notes.
The browser maker underlines that, with cookies shared between sites, tracking companies can tag a user’s browser and follow their browsing activity. Such cookie-based tracking is used for mass commercial tracking, allowing advertising companies to create detailed personal profiles of users.
For more than two years, courtesy of ETP, Firefox has been blocking cookies from companies identified as trackers, but the new feature is meant to take the protections to the next level, and ensure that no cookie can be used to track a user from site to site.
For that, Total Cookie Protection separates cookies by the sites that created them. Thus, when a site or the third-party content on the site stores a cookie in the browser, it is sent to a “cookie jar” assigned to that site, and never shared with other websites.
However, exceptions are made for cross-site cookies needed for non-tracking purposes, such as the cookies used by third-party login providers.
“Only when Total Cookie Protection detects that you intend to use a provider, will it give that provider permission to use a cross-site cookie specifically for the site you’re currently visiting. Such momentary exceptions allow for strong privacy protection without affecting your browsing experience,” Mozilla says.
Related: Google Moves Away From Diet of ‘Cookies’ to Track Users
Related: Google Says Chrome Cookie Replacement Plan Making Progress
Related: Firefox Cracks Down on Supercookies to Improve User Privacy
