Using Compatible Keys for Secure Multicasting in E-Commerce

Consider an electronic commerce (e-commerce) environment where the consumers subscribe to data objects; a server distributes these objects electronically which are then retrieved by the consumer. We propose a protocol showing how the distribution of data objects can be done in a secure and efficient manner. In our protocol, (1) consumers who have subscribed for an object can get access to the object only during the period that their subscription is valid, (2) consumers who have not subscribed to an object do not get access to the object, (3) increasing the number of consumers subscribing to an object does not deteriorate the quality of service, (4) multiple key distributions to each consumer is avoided, (5) key management is simple – each consumer just remembers one key, (6) bandwidth requirements are low, and (7) large processing overhead required for decryption is not incurred by the consumer. The protocol is based on the theory of compatible keys which we illustrate in this paper.