How does browser identification work under dovekey for frequency-capping purposes?

[PedroAlvarado]

That is, how is a Dovekey server able to count that a particular browser instance has seen an ad too many times? It seems that browsers will be required to provide a strong signal, albeit an encrypted one, that distinguishes one browser from another.

[gangwang-google]

Thank you for your question.

The details need to be worked out with browser vendors. The high level idea is that, whenever an ad is rendered, the ad tells the browser its associated FCAP ID and FCAP rules. For each FCAP ID, The browser looks back the most recent N minutes/hours/days defined by the FCAP rule, and counts the number of times that ads were rendered with the FCAP ID.

For details please see Section Frequency capping (FCAP).