Who primarily uses Mode 4?

Mode 4 is primarily utilized by military forces, and it specifically involves encrypted communication. This mode is designed to enhance the security of transponder signals against identification and tracking by unauthorized entities. In military operations, the requirements for secure and reliable communication are critical, particularly to prevent interception or spoofing during missions.

The encryption employed in Mode 4 allows military personnel to identify friendly units while minimizing the risk of the information being exploited by opponents. This capability is vital in combat scenarios where situational awareness and the integrity of communications can significantly impact operational success.

While other groups, such as government agencies or private sector users, may use various identification modes for surveillance or tracking, Mode 4's encryption feature specifically caters to the needs of military applications, making it the primary user group for this mode.