A system to control data exchange, comprising: a content provider ; an encryptor to, for each partner domain in a list of partner domains: generate a partner domain-specific identifier; and encrypt the partner domain-specific identifier and a first authentication token using an encryption key of the corresponding partner domain; a network interface to: transmit to the content provider the encrypted partner domain-specific identifiers and the encrypted first authentication tokens for each partner domain in the list of partner domains; receive, from the content provider, a content item selected by the content provider based on data from each partner domain in the list of partner domains, wherein the data from each partner domain in the list of partner domains is selected based on receiving the encrypted partner domain-specific identifier; receive, from the content provider, a second authentication token for each partner domain in the list of partner domains; and an audit engine to determine to display the content item based on a comparison of the first authentication token for each partner domain in the list of partner domains and the second authentication token for each partner domain in the list of partner domains. a content provider ; an encryptor to, for each partner domain in a list of partner domains: generate a partner domain-specific identifier; and encrypt the partner domain-specific identifier and a first authentication token using an encryption key of the corresponding partner domain; generate a partner domain-specific identifier; and encrypt the partner domain-specific identifier and a first authentication token using an encryption key of the corresponding partner domain; a network interface to: transmit to the content provider the encrypted partner domain-specific identifiers and the encrypted first authentication tokens for each partner domain in the list of partner domains; receive, from the content provider, a content item selected by the content provider based on data from each partner domain in the list of partner domains, wherein the data from each partner domain in the list of partner domains is selected based on receiving the encrypted partner domain-specific identifier; receive, from the content provider, a second authentication token for each partner domain in the list of partner domains; and transmit to the content provider the encrypted partner domain-specific identifiers and the encrypted first authentication tokens for each partner domain in the list of partner domains; receive, from the content provider, a content item selected by the content provider based on data from each partner domain in the list of partner domains, wherein the data from each partner domain in the list of partner domains is selected based on receiving the encrypted partner domain-specific identifier; receive, from the content provider, a second authentication token for each partner domain in the list of partner domains; and an audit engine to determine to display the content item based on a comparison of the first authentication token for each partner domain in the list of partner domains and the second authentication token for each partner domain in the list of partner domains. <EOS>