> Why don't they use encryption? Wouldn't it be preferable for your messages to be completely inscrutable? They don't? The letters read out in a phonetic alph

> Why don't they use encryption? Wouldn't it be preferable for your messages to be completely inscrutable? They don't? The letters read out in a phonetic alphabet are most certainly a code that's completely inscrutable without a codebook, which is probably rotated frequently. Encryption like we use it (e.g. encode arbitrary messages) is probably unnecessary and too complicated. All they're probably trying to do is transmit an authenticated order to execute an action that's been agreed upon ahead of time.