|That's a slam dunk.
6. Yes, the encryption really is secure. It's the people who use it who often are not. Too many people who use the secure telephone unit (STU-III) gossip and try to talk around a sensitive subject before turning the key to switch on encryption. A defector from one of the foreign intelligence services that monitor U.S. communications reported that STU-III encryption is unbreakable. However, he also advised that the chitchat that occurs before the STU-III encryption is switched to secure mode, and after it is taken off secure mode, is a bonanza of valuable information for that country's intelligence service.
Communications monitors can identify STU-III lines. Foreign intelligence services know that the people using these lines have access to sensitive information. As a result, these phone numbers are obvious targets. A STU-III line being used in non-secure mode may be more likely to be monitored than another line that never carries encrypted communications.
Related Topics: Intercepting Your Communications, Using the STU-III.