The Secure Distribution of Digital Contents

E. von Faber, R. Hammelrath & F. Heider

Electronic commerce systems dealing with the distribution of digital contents like software or multimedia data have to couple the use of the provided digital goods with a prior payment for the goods in a way which cannot be by-passed. The basic idea of one possible solution is to distribute the contents in encrypted form, and to have the customer pay for the key which he needs to transform the encrypted content in an accessible form. The security problem can in this way be put into a problem of key distribution.

An architectural design was developed which is independent from the use of a specific payment system or payment protocol. In this paper a description of the system, the basic message formats, and the software components will be given. Four major Parties are involved in our System: the Information Provider, who distributes digital contents in encrypted form, a Key Distribution Center, holding the keys for the contents to be decrypted, the Payment Center, permitting the distribution of the appropiate key after settling of the fees dued by the Customer, who will enjoy the decrypted digital contents. The Paper explains the exchange of information between these parties as a collection of basic protocols, and outlines the overall system architecture.