Google has a(nother) technology to replace tracking cookies

Topics API replaces FLoC, which in turn was designed to replace tracking cookies

Google has presented a new proposal to replace invasive third-party tracking cookies in Chrome, which are used in targeted advertising, while still enabling advertisers to buy ads based on users' browsing interests.

Dubbed Topics API, Google says the system will give users more control over the tracking process, while making them less individually identifiable.

It builds on the lessons Google learned from its Federated Learning of Cohorts (FLoC) trial last year, which prompted a backlash from other tech firms and browser makers.

"Today, we're announcing Topics, a new Privacy Sandbox proposal for interest-based advertising," said Vinay Goel, product director for Privacy Sandbox and Chrome.

"Topics was informed by our learning and widespread community feedback from our earlier FLoC trials, and replaces our FLoC proposal," he added.

Today, advertisers collect user information from browsers using third-party cookies, and use the data to make advertising campaigns more effective. Critics have long raised concerns that companies and malicious individuals can use cookies to track users around the Internet.

Some browsers, like Firefox and Safari, have already introduced measures to block third-party cookies.

Google proposed its own plan to eliminate third-party trackers in Chrome in 2019, through an initiative called Privacy Sandbox. The company said Privacy Sandbox would make web surfing more private, without killing ad tech firms' business model.

As part of the scheme, Google proposed storing and processing all user data in the web browser, and using machine learning algorithms to assess users' interests to target them with relevant ads. Data would be presented to advertisers in the form of a cryptographic token that would hide identifying information. This would enable advertisers to confidently target their ads, without directly identifying individuals.

However, critics said the scheme would remove advertising, login, and many other features from the open web and place them under Google's control. Concerns were also raised about whether Google's proposals were in line with Europe's GDPR data protection regulation.

Google announced FLoC last year as part of Privacy Sandbox, hoping it would be the user tracking technology to kill cookies. FLoC was intended to allow advertisers to target groups of users, based on similar browsing history.

However, among the concerns raised over FLoC was that groups could be small enough to individually track users. The backlash forced Google to rethink its strategy.

Now Google says it is scrapping its old plans in favour of Topics API.

Google has posted information about its new proposal in developer docs, on a GitHub page, and on a Privacy Sandbox site.

Topics API will - like FLoC - enable websites serve ads to users based on their interests, without actually collecting huge amounts of data about them.

For the system to work, Chrome will determine which topics best represent a user's internet activity that week, such as 'fitness', 'sports', and 'travel & transportation'. It will store the information from the past three weeks, and delete older data.

The entire process is designed to take place on the user's device, without involving any external servers, including Google servers.

"When you visit a participating site, Topics picks just three topics, one topic from each of the past three weeks, to share with the site and its advertising partners," Goel said.

Google will build user controls for the system into Chrome, allowing users to see the topics stored, remove any they don't like, or disable the feature completely.

The company will launch a developer trial of the technology in Chrome soon, enabling web developers and the ad industry to try it out.

The final form of Topics API and how it will work will be decided based on feedback.