Design And Rearsh On Broadcast Encryption Scheme

A broadcast encryption scheme is used whenever a broadcaster wants to send messages to several recipients using an unsecured channel. Such a scheme actually allows the broadcaster to choose dynamically a subset of privileged users inside the set of all possible recipients and to send a ciphertext, readable only by the privileged users. This kind of schemes is helpful in numerous commercial applications such as the broadcast of multimedia content or pay-per-view television.In such scenarios, it is also desirable to have a Tracing Mechanism, because many users may collude.That is to say,by their own keys,they can create a new key which can also decrypt the ciphers.In Tracing Mechanism, each subscriber has a decryption key that is associated with his identity and the distributor (or the authorities) possesses a "traitor tracing" procedure that, given the pirate decoder,is capable of recovering the identities of at least one of the traitors.In this paper, the development history and the research's present situation of broadcastencryption are summarized firstly, and the relevant knowledge about cryptology in the broadcastencryption is discussed. By cryptology theory and elementary tools, a broadcastencryption scheme with efficient traitor tracing scheme is presented.In this paper ,we present a public key broadcast encryption scheme based on bilinear pair and LFSR sequence. The encryption algorithm is provably secure and the scheme is collusion resistant. When a pariate box is found ,traitors can be traced by black-box tracing,and the tracing algorithm is deterministic.In addition,the time we must compute has nothing to do with the number of users when tracing.We can trace traitors computing only once.