Conference keys are secret keys used by a group of users commonly and with which they can encipher (or decipher) messages such that communications are secure. Based on the Diffie and Hellman’s PKDS, a conference key distribution scheme is presented in this paper. A sealed lock is used to lock the conference key in such a way that only the private keys of the invited members are matched. Then the sealed lock is thus made public or distributed to all the users, only legitimate users can disclose it and obtain the conference key. In our scheme, the construction of a sealed lock is simple and the revelation of a conference key is efficient as well.