A tracker can no longer follow you from one site to the next
The biggest anti-tracking upgrade yet, and the truest expression of the idea that your memory is yours. A company that follows you around the web by quietly embedding itself on the sites you visit can no longer recognize you from one site to the next. Anything such a third party stores on your device is now kept in a separate box for each site you were actually on, so those visits cannot be joined into one profile - the same cross-site tracking that third-party cookies were banned for, closed here too and for storage as well. Your own sites keep their data exactly as before; nothing you rely on moves. This release also enforces a site's security policy when it arrives as a response header, not only when it is written into the page, so a script the site itself forbids can no longer slip in. Everything is decided and kept on your device. The security architecture aspect moves 53 to 56; the overall platform score stays at 70.