1. A method of conducting a secure transaction with an on-line service while offline comprising the steps of issuing a transaction authorization token to a user from an application server for the on-line service while the user is online; preparing an off-line transaction object containing data to specify and request the transaction; sending a message to the on-line service, said message containing the transaction object and the authorization token; upon receipt of the message, the application server validating the token to authenticate the user and to authorize the transaction; and executing the transaction object if the transaction is authorized.