Firefox 86 with third party cookie blocking appears
Mozilla has released Firefox 86. This includes Total Cookie Protection, a way of placing third-party cookies in silos that prevent users from being tracked across multiple websites. Some functional cookies can still do that.
Firefox 86 is now available for download for all users. There are a number of new features, including the ability to view multiple videos via picture-in-picture. The print function has also been improved. This will include better integration with the computer’s print settings.
The most important addition is that of Total Cookie Protection. In addition, each tracking cookie that follows users across multiple websites is placed in a silo so that they can no longer be shared with other websites. The feature is part of Enhanced Tracking Protection. That blocks cookies based on a list that Disconnect maintains, but domains that are not included can still track users. Total Cookie Protection should also prevent that.
Mozilla uses a technology that it calls State Partitioning. It doesn’t need a list, but uses that new technology to identify whether a third-party cookie is trying to track someone across websites. For this, a cookie from, for example, Facebook is extended from https://facebook.com to https://facebook.com^http://trackingwebsite.com. That way, Firefox can see when a tracking cookie tries to track a user across different websites.
According to Mozilla, an exception is made for certain cookies that are functional in tracking users. As an example, the company mentions cookies that are necessary for single sign-on, for example via the Facebook Login button. Developers don’t have to change anything for that. Firefox can see for itself when a cookie is ‘unpartitioned’ and present the user with a pop-up asking whether a site can still place a tracking cookie for SSO. Users can also allow from the URL bar itself which sites may place cross-site cookies.