Abstract: This disclosure relates to a method for anonymous attestation that includes receiving, by an application running on a client device and from a first content provider, an authentication request to authenticate a user to receive content from a second domain of a second content provider, redeeming, with an attestation token issuing system that issued an anonymous attestation token attesting to the user's authentication to the second content provider, the anonymous attestation token by transmitting the anonymous attestation token with a second request, receiving a redemption result representing whether the attestation token was successfully redeemed, signed by the attestation token issuing system using a digital signature and is operable to verify, to the second content provider, that the user is authenticated to the second content provider without identifying the user to the second content provider, and transmitting, to the first content provider, the redemption result.