Course 734: COMSEC custodian refresher


This course will provide you with an overview of key concepts associated with COMSEC, pertinent COMSEC Custodian functions and the most common COMSEC incidents reported to, and evaluated by, the Communications Security Establishment (CSE). As a Custodian, you already have the knowledge and professional experience by performing the duties expected of this role, and as such we will focus your attention to the current policies and procedures associated to these concepts. Additionally, you will be provided with solutions and/or mitigation measures designed to limit the impacts of these incidents through specific examples and realistic scenarios that you may encounter.


The objective of this course is to ensure that upon successful completion, you will be able to identify foundational COMSEC concepts reinforce key policies, and procedures that are related to the most common COMSEC incidents and reduce the associated errors. Upon successful completion of this course, you will be able to reduce or eliminate potential vulnerabilities when using Government of Canada (GC) classified systems and Accountable COMSEC Material (ACM).

Course outline

This online course is composed of 7 modules. The course modules are as follows:

  • Module 1 – COMSEC fundamentals
  • Module 2 – Unauthorized extension of a cryptoperiod
  • Module 3 – Permanent loss, temporary loss, and found ACM
  • Module 4 – Late and improper destruction of key
  • Module 5 – Malfunctioning and damaged/tampered ACM
  • Module 6 – Packing and shipping errors
  • Module 7 – Unauthorized/inappropriate use of ACM
  • Final exam

Target audience

GC COMSEC Custodians. All Custodians are highly encouraged to revalidate their formal training requirement every 5 years by successfully completing this course and exam. Newly appointed Custodians are still required to take the 230 COMSEC account management in the GC instructor-led course. Individuals who likely need or should seek out this training may include personnel who have worked for many years in COMSEC, likely within a departmental silo, and who require an update on the latest COMSEC policy and doctrine releases and current best operational practices.


Completion of the 230 COMSEC account management in the GC instructor-led course, or an equivalent as defined by a Prior Learning Assessment and Recognition (PLAR), is a prerequisite. It contains invaluable information and remains mandatory for all new Custodians. This refresher is not intended to replace it.


This course is presently in a beta version. As experienced COMSEC Custodians, the feedback you provide after completing this course will help us improve the content and confirm if we have met the expectations for this refresher course.

The first time you take this course, it is recommended you complete the modules in sequential order. Only when you have completed all 7 modules, should you attempt the final exam. Once you have successfully completed the final exam by achieving a passing grade of 80%, you will be able to print or save your certificate. You may also return to this course at any time for refresher purposes.

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