Abstract: An interface between a digital communication system and a PSTN establishes a user configurable secure encrypted link to a digital subscriber unit through the digital communication system, and provides clear (unencrypted) voice to telephone sets through the PSTN. The interface includes a security module for encrypting and decrypting information with user specific algorithms and keys, a transcoder for converting modulated voice to digital voice and a modem for modulating and demodulating data and encrypted voice. Accordingly, the wireline interface allows for user specified security over a digital wireless portion of an end-to-end communication channel. The interface also provides for the communication of unencrypted voice followed by secure voice or secure data.
Type:
Grant
Filed:
July 30, 1998
Date of Patent:
March 12, 2002
Assignee:
General Dynamics Decision Systems, Inc.
Inventors:
Douglas Allan Hardy, Peter J. Armbruster