technology techniques agent handling concealment device covert agent covert listening device cut cyber spying dead drop false flag operations honeypot impersonation impostor interrogation non official cover numbers messaging official cover one way voice link sabotage safe house side channel attack steganography surveillance surveillance aircraft '''source ''' ref name protocol organization intelligence officer 's clothing accessories behavior must unremarkable possible lives others' may depend spy person employed seek top secret information source ref name bar ref within united states intelligence community asset common usage case
Applied science Military sciences Espionage