An intelligent and efficient traitor tracing for ubiquitous environments

Broadcast encryption has been applied to transmit digital information such as multimedia, software and paid TV programs on the open networks. One of key factors in the broadcast encryption is that only previously authorized users can access the digital information. If the broadcast message is sent, first of all, the privileged users will decode the session key by using his or her personal key, which the user got previously. The user will get the digital information through this session key. As shown above, the user will obtain messages or session keys using the keys transmitted from a broadcaster, which process requires effective ways for the broadcaster to generate and distribute keys. In addition, when a user wants to withdraw or sign up, an effective process to renew a key is required. It is also necessary to chase and check users’ malicious activities or attacking others. This paper presents a method called Traitor Tracing to solve all these problems. Traitor tracing can check attackers and trace them. It also utilizes a proactive scheme for each user to have effective and intelligence renewal cycle to generate keys.