Broadcast encryption allows a sender to securely broadcast to any subset of the group members.However

its security heavily depends on broadcast centre to generate and distribute decryption secret keys for group members.In order to solve the above problem

we propose the notion of certificate-based broadcast encryption

describe the formal definition and security model of the certificate-based broadcast encryption.Furthermore

we also provide an efficient certificate-based broadcast encryption scheme.In our scheme

the decryption key includes user's private key and a certificate

where the private key is chosen by user himself

and the certificate is generated by certification authority.Therefore

our scheme overcomes the key escrow problem.In addition

our scheme is efficient

because it needs only one paring in decryption algorithm and paring operation in encryption algorithm can be pre-computed.