On key distribution in secure multicasting

Multicasting has been widely utilized for delivering messages from one sender to multiple recipients. Nowadays in some applications such as pay per view or videoconferencing systems, the messages delivered via multicasting should be available to authorized recipients only. Therefore, secure multicasting becomes an important design issue in distributed environment To achieve secure multicasting, all authorized recipients form a group and share a group key; messages should be encrypted by the key before they are multicasted. For the sake of security, we need a new group key if someone joins/leaves the group. Consequently, our goal is aimed at finding a way to distribute the new key securely and efficiently. In this paper; we propose a new solution to the problem; we distribute new keys through a special function called secure filter: Compared with related work our solution requires less system resources to change group members.