Cryptography – Communication system using cryptography – Data stream/substitution enciphering
Patent
1990-10-31
1992-02-25
Tarcza, Thomas H.
Cryptography
Communication system using cryptography
Data stream/substitution enciphering
380 49, 380 9, H04L 900
Patent
active
050919415
ABSTRACT:
In the secure radio transmission system of the present invention the sign bit for each byte of audio digital data is scrambled to generate a scrambled sign bit. By altering the sign bit, the resultant sound is significantly affected regardless of the amplitude range of the source audio. A key is stored in each authorized radio transmitter/receiver telephone. The key is used to select the bits of the digital voice data to be transmitted which are used to scramble the sign bit. The selected bits of the voice data are then used to scramble the sign bit and the voice data with the scrambled sign bit are transmitted to the receiving device. The receiving device executes the reverse process wherein the receiving device selects predetermined bits of the received voice data according to the key stored in the receiving device and scrambles the scrambled sign bit using the same algorithm in accordance with the data bits selected. This process generates the unscrambled sign bit and unscrambled voice data is generated at the output of the receiving device.
REFERENCES:
patent: 4179586 (1979-12-01), Matthews et al.
patent: 4658094 (1987-04-01), Clark
patent: 4972469 (1990-11-01), Saltwick et al.
patent: 5007086 (1991-04-01), Shenoi et al.
Needle David L.
Stribling Bradley C.
Cain David
Rose Communications, Inc.
Tarcza Thomas H.
LandOfFree
Secure voice data transmission system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Secure voice data transmission system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Secure voice data transmission system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1898463