Abstract: Considering the special application scenario of the cross-regional operation, we have studied the group function of the communication system aiming at the problem in the development process of cross-regional command and communication system. Due to the characteristics of confidentiality and secrecy of operation, we propose and design the reliable information guidelines. After our approach has come to use, a good effect is gained in practice. It proves the effectiveness of group function which improves the communication efficiency. And the function of reliable information guidelines greatly enhances the security of the communication process.

Key words: cross-regional, group communication, encryption, time-synchronized