Systems and methods in which an intermediary server provides a proxy token value in lieu of a stable token value to a third-party. The intermediary server identifies a stable token value associated with a first-party and accesses a knowledge base to determine a length of time since a third-party used a first proxy token value in a prior action, where the first proxy token value had previously been presented to the third-party in lieu of the stable token value. The intermediary server determines that the length of time since the third-party used the proxy token value in the prior action exceeds a maximum reliability time threshold and, responsive to the determination, generates a second proxy token value. The intermediary server then provides, to the third-party, an invitation to use the second proxy token value in an action, the invitation omitting the stable token value and the first proxy token value.