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STE Service Interrupt Circuit (SIC)


STE Module

Technical Challenge:

If the host computer fails without notice or after hours, calls to the STE Re-key system will go unanswered creating a denial of service.


The intended use is for the FNBDT STE Re-key system. We have 8 STE Data Devices connected to host computers for remote control. Any FNBDT Desktop/Office STE may call the re-key system to update the key to make secure telephone calls. Often, the application on the host computer will fail during the re-key call. Any new calls to that data device will go unanswered until the application is restarted. The STE SIC will disconnect the phone line from the Data Device thus taking it out of service. This invention eliminates the need for humans to perform the same functions, thus eliminating the need for after hours and constant monitoring. It utilized a modular design using no external power source and a single relay that controls both PSTN and ISDN interfaces.

Demonstration Capability:

A prototype can be successfully demonstrated.

Potential Commercial Application(s):

Mostly Department of Defense and government applications.

Patent Status:

Patent Application has been filed with USPTO. (Updated)

Reference Number: 1366

If you are interested in exploring this technology further, please express your interest in writing to the:

National Security Agency
NSA Technology Transfer Program
9800 Savage Road, Suite 6541
Fort George G. Meade, Maryland 20755-6541


Date Posted: Jan 15, 2009 | Last Modified: Jan 15, 2009 | Last Reviewed: Jan 15 2009