Group-oriented Encryption Secure against Collude Attack.
Chunbo Ma, Jun Ao, Jianhua Li · 2007
Abstract. A group oriented encryption scheme is presented in this paper. In this scheme, a sender is allowed to encrypt a message using the group public key and send the ciphertext to the group. Any user in the group can independently decrypt the ciphertext via his private key. The scheme is secure against adaptively chosen ciphertext attack and collude attack.