| |
 |
|
Class Information
Number: 380/38
Name: Cryptography > Communication system using cryptography > Frequency shift or inversion
Description: Subject matter which modifies a segment of the frequency spectrum of the information signal.
Sub-classes under this class:
Patents under this class:
| Patent Number |
Title Of Patent |
Date Issued |
| 7391867 |
Graphical display of QKD system statistics |
Jun. 24, 2008 |
| 7379878 |
Information encoding apparatus and method, information decoding apparatus and method, recording medium utilizing spectral switching for embedding additional information in an audio signal |
May. 27, 2008 |
| 7333608 |
Analog scrambler |
Feb. 19, 2008 |
| 7298840 |
Method and system for data integrity protection |
Nov. 20, 2007 |
| 7219082 |
Financial management system |
May. 15, 2007 |
| 7076659 |
Enhanced method for digital data hiding |
Jul. 11, 2006 |
| 7051203 |
Data watermarks created by using an uneven sampling period |
May. 23, 2006 |
| 6993153 |
Self-orienting watermarks |
Jan. 31, 2006 |
| 6973190 |
Method for protecting an electronic system with modular exponentiation-based cryptography against attacks by physical analysis |
Dec. 6, 2005 |
| 6973188 |
Analog scrambler |
Dec. 6, 2005 |
| 6970843 |
Financial management system |
Nov. 29, 2005 |
| 6823455 |
Method for robust watermarking of content |
Nov. 23, 2004 |
| 6731757 |
Multichannel digital signal generation method and apparatus |
May. 4, 2004 |
| 6625297 |
Self-orienting watermarks |
Sep. 23, 2003 |
| 6501841 |
Method for providing security for a transmission of information through a plurality of frequency orthogonal subchannels |
Dec. 31, 2002 |
| 6389138 |
Method and apparatus for generating a complex scrambling code sequence |
May. 14, 2002 |
| 6345100 |
Robust watermark method and apparatus for digital signals |
Feb. 5, 2002 |
| 6229897 |
Apparatus and method of secured analog voice communication |
May. 8, 2001 |
| 6078668 |
Apparatus and method for concealing data bursts in an analog scrambler using audio repetition |
Jun. 20, 2000 |
| 5796838 |
Method and apparatus for performing frequency spectrum inversion |
Aug. 18, 1998 |
| 5768374 |
Apparatus and method for continuous scrambling while transmitting or receiving synchronization data |
Jun. 16, 1998 |
| 5757921 |
Radio communication apparatus having common oscillator applied for PLL, conversion and scramble/descramble circuits |
May. 26, 1998 |
| 5671284 |
Data encryptor having a scalable clock |
Sep. 23, 1997 |
| 5528692 |
Frequency inversion scrambler with integrated high-pass filter having autozero to remove internal DC offset |
Jun. 18, 1996 |
| 5471531 |
Method and apparatus for low cost audio scrambling and descrambling |
Nov. 28, 1995 |
| 5400404 |
Modulation/demodulation circuit and communication system utilizing the same |
Mar. 21, 1995 |
| 5392354 |
Cordless phone system capable of scrambling communication signals |
Feb. 21, 1995 |
| 5377223 |
Notch filtering a spread spectrum signal using fourier series coefficients |
Dec. 27, 1994 |
| 5335279 |
Digital voice-band spectrum inversion apparatus |
Aug. 2, 1994 |
| 5168522 |
Wireless telephone with frequency inversion scrambling |
Dec. 1, 1992 |
| 5159631 |
Audio scrambling system using in-band carrier |
Oct. 27, 1992 |
| 5144666 |
Decoder to decode an encrypted sound |
Sep. 1, 1992 |
| 5140635 |
Wireless telephone with frequency inversion scrambling |
Aug. 18, 1992 |
| 5065430 |
Voice band splitting scrambler |
Nov. 12, 1991 |
| 5058159 |
Method and system for scrambling and descrambling audio information signals |
Oct. 15, 1991 |
| 5020104 |
Method of reducing the useful bandwidth of bandwidth-limited signals by coding and decoding the signals, and system to carry out the method |
May. 28, 1991 |
| 5018198 |
Speech privacy processing method and apparatus therefor |
May. 21, 1991 |
| 4984219 |
Method and apparatus for decoding of frequency inversion based scramblers |
Jan. 8, 1991 |
| 4969191 |
Fully digital phase-locked loop |
Nov. 6, 1990 |
| 4949378 |
Toy helmet for scrambled communications |
Aug. 14, 1990 |
| 4914696 |
Communications system with tandem scrambling devices |
Apr. 3, 1990 |
| 4908860 |
System for the secret transmission of audio signals and television receiver for receiving such signals |
Mar. 13, 1990 |
| 4888799 |
Scrambling of signals by inversion |
Dec. 19, 1989 |
| 4827507 |
Duplex analog scrambler |
May. 2, 1989 |
| 4817141 |
Confidential communication system |
Mar. 28, 1989 |
| 4802219 |
Method and apparatus for distorting a speech signal |
Jan. 31, 1989 |
| 4799257 |
Wireless transmission system for PM modulation signal |
Jan. 17, 1989 |
| 4773092 |
Speech scramblers |
Sep. 20, 1988 |
| 4750205 |
Frequency or time domain speech scrambling technique and system which does not require any frame synchronization |
Jun. 7, 1988 |
| 4747137 |
Speech scrambler |
May. 24, 1988 |
|
|
|
