Mozilla tests privacy-friendly “Prio” technology to gather telemetry data

Mozilla has announced it’s currently testing a privacy-friendly method to collect telemetry data from Firefox Nightly users. To improve browsers, all major browser developers collect statistics and other data about usage of their software.

Mozilla tests privacy-friendly "Prio" technology to gather telemetry data

In case of Firefox, users have to explicitly provide their consent to sent data to Mozilla. Nevertheless, users still have to trust Mozilla that their data isn’t abused, doesn’t leak or is shared with a third party. With the new method, Mozilla aims for a situation where users don’t even have to trust the developer, especially when they share sensitive data.

Therefore, Mozilla has developed a new system together with scientists from the Stanford University. The new system is called Prio. The idea behind Prio is that in most cases it’s not necessary to collect data from individual users, but only aggregated data. Prio makes it possible for Mozilla to collect aggregated data without collecting data that can be traced back to an individual user.


This is possible by splitting the data of users in parts which are both sent to different servers.

“Each Prio client holds a private data value (e.g., its current location), and a small set of servers compute statistical functions over the values of all clients (e.g., the most popular location). As long as at least one server is honest, the Prio servers learn nearly nothing about the clients’ private data, except what they can infer from the aggregate statistics that the system computes,” the Stanford researchers who work on Prio explain.

Mozilla has already tested Prio in Firefox Nightly for 6 weeks and collected  3 million data values.

“Once we’ve validated that it’s working as expected and provides the privacy guarantees we require, we can move forward in applying it where it is needed most,” according to Robert Helmer, a Mozilla engineer who works on analyzing incoming Firefox crashes.