AbstractIn this paper, in order to simultaneously resolve the transmission security and availability in Supervisory Control And Data Acquisition (SCADA) group communications, we propose a robust and efficient group key management scheme, called LiSH+, which is characterized by developing a secure self‐healing mechanism with t‐revocation and collusion resistance capability. A dual direction hash chain is utilized to guarantee the backward secrecy and forward secrecy of group key. A novel self‐healing mechanism is constructed to ensure availability of the group member in case of devices failure and prevent the collusive users from exploiting the group key in the proposed scheme. In addition, the compromised users can be revoked from the group dynamically by broadcasting message. Detailed security analysis shows that the proposed LiSH+ scheme meets the requirements of group communication and is secure in terms of t user collusion‐free. Performance evaluation also demonstrates its efficiency in terms of low storage requirement and communication overheads. Copyright © 2014 John Wiley & Sons, Ltd.