August 9, 2025
2 min read
Private State Tokens (PST) represent a novel approach within Google's Privacy Sandbox initiative aimed at providing privacy-preserving trust signals across websites. Their fundamental purpose is to enable the transmission of user authenticity signals between different web contexts without enabling individual user tracking or compromising privacy.
The PST framework relies on two principal roles:
A critical property of PSTs is the encryption of tokens, which effectively prevents any party from linking token instances back to an individual user. This encryption supports the following:
PSTs provide a mechanism for websites to combat fraud, distinguish bots from humans, and ensure authentic user interactions through a trust signal conveyed without exposing identifying information.
Key findings from recent evaluations indicate:
In summary, Private State Tokens deliver a balance between user privacy and web security, offering a scalable alternative to cookie-based authentication and tracking systems. By leveraging cryptographic guarantees, they mitigate the trade-off between privacy and fraud detection that has historically challenged web ecosystems.
