Where do the keys for the DMR originate from?

The keys for the Digital Modular Radio (DMR) originate from a Daily Comms Message because this message provides the most current and relevant instructions and information necessary for secure communication operations. The Daily Comms Message is typically distributed to ensure that all personnel have access to the latest operational requirements and security protocols, which includes the issuance and validation of cryptographic keys.

In contrast, other options like a Weekly Security Brief, Bi-weekly Command Notification, or Monthly Security Update do not provide the frequency or immediacy needed for the dynamic nature of secure communications, as they are less frequent and may not include the up-to-date key information needed on a daily basis. This makes the Daily Comms Message the most suitable source for the keys used in DMR operations.