Firefox 85, scheduled to be released next month, in January 2021, will ship with a feature named Network Partitioning as a new form of anti-tracking protection.
The feature is based on "Client-Side Storage Partitioning[1]," a new standard currently being developed by the World Wide Web Consortium's Privacy Community Group.
"Network Partitioning is highly technical, but to simplify it somewhat; your browser has many ways it can save data from websites, not just via cookies," privacy researcher Zach Edwards[2] told ZDNet in an interview this week.
"These other storage mechanisms include the HTTP cache, image cache, favicon cache, font cache, CORS-preflight cache, and a variety of other caches and storage mechanisms that can be used to track people across websites."
Edwards says all these data storage systems are shared among websites.
The difference is that Network Partitioning will allow Firefox to save resources like the cache, favicons, CSS files, images, and more, on a per-website basis, rather than together, in the same pool.
This makes it harder for websites and third-parties like ad and web analytics companies to track users since they can't probe for the presence of other sites' data in this shared pool.
According to Mozilla, the following network resources will be partitioned starting with Firefox 85:
- HTTP cache
- Image cache
- Favicon cache
- Connection pooling
- StyleSheet cache
- DNS
- HTTP authentication
- Alt-Svc
- Speculative connections
- Font cache
- HSTS
- OCSP
- Intermediate CA cache
- TLS client certificates
- TLS session identifiers
- Prefetch
- Preconnect
- CORS-preflight cache
But while Mozilla will be deploying the broadest user data "partitioning system" to date, the Firefox creator isn't the first.
Edwards said the first browser maker to do so was Apple, in 2013[3], when it began partitioning the HTTP cache, and then followed through by partitioning even more user