A method of brokering a transaction between a consumer and a vendor by a broker, wherein the consumer, the broker and the vendor are all attached to a public network, the consumer having a secure token containing a true consumer identity. The method comprising the steps of: the consumer obtaining a temporary identity from the broker by using the true consumer identity from the secure token; the consumer selecting a purchase to be made from the vendor; the consumer requesting the purchase from the vendor and providing the temporary identity to the vendor; the vendor requesting transaction authorisation from the broker by forwarding the request and the temporary identity to the broker; the broker matching the temporary identity to a current list of temporary identities, and obtaining the true consumer identity; the broker providing authorisation for the transaction based on transaction details and true consumer identity.