In a multi-receiver encryption environment, a sender can randomly choose a set of authorized receivers while distributing messages to them efficiently and securely. Recently, more and more researchers concern the privacy of receivers. They mentioned that an authorized receiver does not want other entities, except the service provider, to be able to derive her/his identity in many applications such as pay-TV. However, most of these protocols either provide no formal security proofs or are inefficient owing to high computation cost. In this thesis, we construct two provably secure and efficient anonymous multi-receiver certificated-based encryption schemes, PMCE and SCMCE, which avoid the key escrow problem while preserving the implicit certification of identity-based setting. The proposed PMCE and SCMCE get rid of pairing computation to encrypt a message and only need one and two pairing computations to decrypt the ciphertext, respectively. Finally, we define the security models and offer formal proofs to all properties including receiver anonymity.