Secure Terminal Equipment

Secure Terminal Equipment (STE) is the U.S. government's current and encrypted telephone communications system for wired communications ().
It is designed to use ISDN telephone lines. It offers higher speeds of up to 128 Kbit/s. The greater bandwidth allows higher quality voice. They also can also be used for data and fax transmission through a built-in RS-232 port.
STE is intended to replace the older STU-III office system and the KY-68 tactical system.