The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 27, 1998
Filed:
Jun. 07, 1995
Michael Onufry, Jr, Bethesda, MD (US);
Comsat Corporation, Bethesda, MD (US);
Abstract
A digital circuit multiplier (DCM) system which permits encrypted signals to obtain a multiplication gain at the DCM equipment without decrypting the signals at the DCM equipment. Detection of speech/silence is made at the encryption stage and distinct and separable encryptions are applied to the speech and silence portions of the signal, as well as a control signal indicating which portions of the encrypted data stream correspond to speech and silence. At the DCME transmit unit, only the control signal portion of the data stream is decrypted and the encrypted silence frames are discarded to obtain multiplication gain. Thus, efficient use is made of the channel capacity without the need to decrypt the speech signal at the DCME. At the DCME receive unit the control signals are used to add encrypted silence frames back into the data stream. Once the received signals have reached a secure location, the decrypter unit decrypts the speech and silence frames to present a reconstituted speech signal, complete with silent portions, to the end user.