The Cyber Center of Excellence has released ATP 6-02.75 (Techniques for COMSEC Operations). It’s stated purpose is to:
provides guidance on the management, employment, handling, and storage of communications security materials. It outlines roles and responsibilities for all members of the Army Profession providing communications security planning, management, and accounting services in support of movement and maneuver, intelligence, fires, sustainment, mission command, protection, and the Army’s portion of Department of Defense information networks (DODIN) capabilities. This publication addresses methods of key transport, provides the fundamental principles for communications security operations to support all echelons, and provides details of Key Management Infrastructure (KMI).
You can download the document at here.