A Scalable and Secure Key Distribution Mechanism for Multicast Networks

The benefits of multicasting are becoming evermore apparent and its usage is getting more importance than ever. Providing security services for multicast, such as traffic integrity, authentication and confidentiality is challenging since it requires secure distribution of group key to each of the group members. Traditionally, the key distribution function has been assigned to a central network entity, or Key Distribution Center (KDC), but this method does not scale for wide-area multicasting. Our proposed scheme provides a scalable solution to multicast key distribution problem. The proposed scheme uses the core based tree (CBT) architecture to distribute the session key to group members. We use combination of public and secret key cryptosystem to improve speed and security of the scheme. We assume that the intermediate nodes in CBT are trusted. We have also introduced the concept of forwarding key to improve the performance of the scheme.