"... how do they fit together with the cheap phone and dead-drops? ..." If you don't want anyone to know you are sending a message to another person you encryp

"... how do they fit together with the cheap phone and dead-drops? ..." If you don't want anyone to know you are sending a message to another person you encrypt a message & leave it at a specific place with a marker. I assume you get this. But if you give a call with an an encrypted message on any phone you potentially give the game away. With a cheap $20 phone used minimally or once, sending a hand encrypted message using Solitaire you get anonymity and security.