Abstract: Consider the following situations: there are two companies A and B, and they want to communicate with each other over the Internet. In order to generate a secure signature on behalf of the company A, A requires that only enough members in A can generate a valid signature by cooperation. At the same time, company A wants only the designated receiver who can verify the signature. Motivated by this consideration and the necessity of protecting the security of original information, this paper, which combines the sharing secret technology and Chameleon function, presents a new signature based on bilinear pairing. It is only the designated receiver that can verify the signature and can't convince the third party of the valid signature. It is undeniable and when a dispute occurs, the signer can prove the sig