ID-Based Designed-verifier Multisignature without Trusted PKG

An ID-based designed-verifier multisignature without trusted PKG is proposed. In proposed scheme, several signers cooperate to sign a single message and no one else than the designed verifier can be convinced by this signature. Since the scheme is based identity, it simplifies the certificate management. It is no need to trust PKG completely, so dishonest PKG can not be free to impersonate a user to sign a message and engage in malicious activities. We also presented the exact proof that the proposed scheme is security.