What is Google Cohorts (FLoC), is it safe, and how is it different from cookies

17.06.21 IT / Safety 4807

Google Cohorts are just groups that are formed according to certain preferences. In contrast to the orientation for one user, it is much easier to select content for a group of users. This can be used for advertising purposes, which was done by Google - FLoC technology (Federated Learning of Cohorts) was introduced.

This technology is being implemented in modern versions of browsers from Google (Chrome), while this is in the nature of testing. How does FLoC work ? The user, when visiting any page of the site, leaves a history in the browser, on the basis of which the browser assigns this user to a group of the same subject. Such groups have their own identifiers (Groupe ID) - data is stored on the client side and is also sent to processing servers.

However, this technology has its drawbacks in terms of security and privacy of personal preferences. This is exactly what other browser developers, such as Firefox, Opera, etc., have announced. After all, there is a potential opportunity to calculate the user, find out his preferences, to which groups he belongs. All this makes his personal preferences a target for cybercriminals, since it is possible to calculate the interests of the user and, based on them, launch attacks.

The difference between FLoC technology and Cookie is quite obvious, Cookies are stored only in the browser and, if used correctly, meet basic user security standards. While enrolling a user into a cohort (group) and then sending such information to partners and various companies is obviously not the safest way to personalize the content and functionality of the site.

errors may occur when working with FLoC , for example, error:

Error with Permissions-Policy header: Unrecognized feature: 'interest-cohort'.

This means that you need to revise the site settings, add the correct conditions for sending headers, etc. Also, do not forget about the FLoC compatibility with different browsers, as the technology is new.