Communications security (COMSEC) involves the protection of voice, data, and facsimile signals during transmission. Rapidly advancing technology and the ease with which communications systems can be monitored and exploited by criminal elements or hostile intelligence services presents a serious challenge to the legal and law enforcement community.

Within each USAO, the DOSM oversees communications security and determines USAO requirements for secure telephone and facsimile equipment, and promotes the use of secure communications equipment among district personnel. The COMSEC Representatives are responsible for day-to-day management of secure communications equipment, maintaining required accounting records, and conducting periodic inventories of COMSEC equipment and material.

[updated February 2018