WTF are private state tokens in Google’s Privacy Sandbox?

The third-party cookie’s deprecation — and broader crackdown on cross-site tracking practices, such as device fingerprinting — comes with side effects. One side effect is losing the means for companies to combat bot traffic. To account for this consequence, Google’s Privacy Sandbox features a proposal for fighting fraudulent traffic called Private State Tokens.

Private State Tokens effectively have sites that are able to authenticate site visitors be the ones to vouch for those visitors’ authenticity so that they can be trusted by other sites. As broken down in this explainer video, it’s akin to a friend recommending a therapist to another friend — albeit with the web browser providing a privacy-preserving means for passing on that recommendation.