Performing a business transaction without disclosing sensitive identity information to a relying party

A user engages in a transaction with a relying party. The relying party requests identity information from the user in a security policy and identifies transaction elements for an on-line business transaction. Typically, the security policy and transaction elements are transmitted together; the security policy can be as little as a request to conduct the on-line business transaction. The user identifies an information card that satisfies the security policy. The computer system requests a security token from the identity provider managing the information card, which can include requesting a transaction receipt for the transaction elements. The computer system then returns the security token (and the transaction receipt) to the relying party, to complete the transaction.