Firefox to implement network partitioning as an answer to tracking

From v85 and onwards, Firefox will ship with network partitioning as an anti-tracking defence.

The new feature is scheduled to go live in January 2021.

It is based on what is known as ‘client-side storage partitioning’, a new standard developed by the World Wide Web Consortium’s Privacy Community Group.

Simply put, it is another way for your browser to store data from websites apart from the traditional way – via cookies.

Zach Edwards, a privacy researcher, revealed some of the other storage mechanisms:

  • Font cache
  • HTTP cache
  • Favicon cache
  • CORS-preflight cache
  • Image cache

Network partitioning, however, will introduce the concept of saving resources on a per-website basis instead of storing everything in the same pool.

When it goes live, websites and third-party actors such as web analytics solutions will have a harder time tracking users as probing for data deposited by other websites will no longer be an option.

In particular, network partitioning will affect the following:

  • StyleSheet cache
  • Image cache
  • Alt-Svc
  • TLS client certificates
  • Preconnect
  • CORS-preflight cache
  • OCSP
  • Favicon cache
  • Connection pooling
  • Speculative connections
  • HTTP cache
  • Font cache
  • HSTS
  • Intermediate CA cache
  • HTTP authentication
  • TLS session identifiers
  • Prefetch
  • DNS

Although Mozilla’s partitioning system is the broadest seen to date, it is by no means the first such system.

In fact, Apple was the first browser maker to pioneer HTTP cache partitioning.

With the release of Chrome 86, Google seems to be following in the same footsteps.

Upon release, Mozilla expects some performance issues – however, it has decided that user privacy is worth the sacrifice.

Edwards said that digital strategists are working hard to bring an end to third-party cookies.

Mozilla’s approach is expected to block ‘supercookies’ better.

Supercookies are a type of browser cookie that attempts to take advantage of various shared storage mediums to track users.