The Templars of Twilight utilized various methods for communication both inside their space and outside it. Following is information about these methods.
Intraship Communication was very secure, comprising almost entirely of 'physical line' communications. All primary and most secondary communication terminals are connected to a wired network that runs through out the ship. This way communications can't be observed without directly tapping into the ships hardline and that would be unlikely in most cases do to tight security.