Parties involved in a transaction in an E-marketplace identify characteristics of a transaction that they are willing to accept and/or that they can provide. To do this, an attribute certificate is created for each party that contains the attributes of a buyer, seller, or third-party participant who will be transacting business in the particular E-marketplace. The attributes pertain to specifics of the transaction. The party submitting the attribute also identifies alternative conditions which, if they exist would be acceptable for conducting the transaction. Once these criteria, in the form of the attribute certificates, are received by the E-marketplace, the E-marketplace verifies the attributes. A server in the E-marketplace is configured to determine various combinations of participants that can match the deal criteria. In this manner, the E-marketplace “choreographs” the transaction to meet the needs of all.