| 6690812 |
Watermark insertion and extraction into and from a high quality signal is performed using sample rate conversion |
| Feb-10-2004 |
A high-quality signal, for example, a unity-bit coded (DSD) audio signal having a 2.822 MHz bit rate (fs1) is converted to a lower sample rate (fs3) PCM signal by a sample rate converter (102). The watermark... |
| 6425082 |
Watermark applied to one-dimensional data |
| Jul-23-2002 |
In the process of embedding watermark information in one-dimensional source data, first spread one-dimensional data x(t) is generated by subjecting one-dimensional source data s(t) to spectrum-spreading... |
| 6597789 |
Video/audio scrambling with single conversion tuners |
| Jul-22-2003 |
Conventional decoding systems for scrambled audio-visual signals are improved by providing a dual-side local oscillator that functions as a high-side oscillator if the incoming RF signal is unscrambled... |
| 6937728 |
Verifiable anonymous channel |
| Aug-30-2005 |
Two El Gamal ciphertexts, which are input to a two-input two-output unit switching gates SW forming a permutation network, are randomized with a random number and randomly permuted, and a zero-knowledge... |
| 4654705 |
Two channel audio scrambling system |
| Mar-31-1987 |
A two channel audio scrambling circuit for a television signal encoding system includes synchronized digital carrier switching means for deriving two suppressed carrier, switched audio signals that are... |
| 4910771 |
Television signal converter |
| Mar-20-1990 |
A television signal converter includes a CATV tuner having a channel converting function, a gain changing circuit for descrambling the output from the CATV tuner and the like, in order to convert a television... |
| 4908860 |
System for the secret transmission of audio signals and television receiver for receiving such signals |
| Mar-13-1990 |
Encoding is realized by means of a first low-pass input filter (21), a first modulator (20), a second low-pass filter (19), a second modulator (18) whose modulating signal has a frequency which is pseudo-random... |
| 6571144 |
System for providing a digital watermark in an audio signal |
| May-27-2003 |
The foregoing problems are solved and a technical advance is achieved by a computer-implemented system for providing a digital watermark in an audio signal. In a preferred embodiment, a audio file, such... |
| 4922532 |
Sync suppression scrambling and descrambling of television signals for subscription TV |
| May-1-1990 |
The quality of sound delivered to a subscriber viewing a channel which has been scrambled using sync suppression scrambling, particularly when the program is being transmitted with stereo sound, is improved... |
| 4222068 |
Subscription television apparatus and methods |
| Sep-9-1980 |
Subscription apparatus and methods wherein an encoder begins inversion of a video signal during the last horizontal trace line of a randomly selected vertical interval and continues to invert trace lines... |
| 7020285 |
Stealthy audio watermarking |
| Mar-28-2006 |
Described herein is technology for inserting and detecting watermarks in signals, such as a music clip. In one described implementation, a watermarking system employs chess spread-spectrum sequences (i.e.,... |
| 3936594 |
Secure television system |
| Feb-3-1976 |
A secure system for television transmission wherein a television signal is transmitted on one frequency channel and a composite high fidelity stereophonic audio signal is transmitted on a separate unrelated... |
| 5430798 |
Scrambled TV-IF signal transmission system |
| Jul-4-1995 |
A cable TV signal transmission system comprising a Nyquist filter carrier recovery circuit, a mixer, a level shifter and a pre-emphasis circuit for transmitting scrambled TV-IF signals on an FM or digital... |
| 4075660 |
Pay television system with synchronization suppression |
| Feb-21-1978 |
Reference pulses of opposite polarity to the horizontal sync pulses are added to the composite television signal just preceeding each horizontal sync pulse. The video portion of the signal is inverted... |
| 4410911 |
Multiple signal transmission method and system, particularly for television |
| Oct-18-1983 |
A method and system for scrambling a plurality of input signals for secure transmission thereof, as well as various methods and systems for television transmission, are disclosed. The disclosed scrambling... |
| 4398216 |
Multiple signal transmission method and system, particularly for television |
| Aug-9-1983 |
A method and system for scrambling a plurality of input signals for secure transmission thereof, as well as various methods and systems for television transmission, are disclosed. The disclosed scrambling... |
| 7020286 |
Modulation of dynamical systems for communication |
| Mar-28-2006 |
A system for modulating and demodulating signals that provides a new class of signal modulators and their corresponding demodulators. The modulation scheme embeds in an information signal a carrier signal... |
| 4956862 |
Method of providing sound privacy system compatible with mono and btsc stereo audio |
| Sep-11-1990 |
In order to provide secure access to the audio portion of a television signal, the audio portion of a TV signal is modulated at a frequency that is offset from the standard carrier frequency. In the embodiment... |
| 6697942 |
Method for remotely managing a remote device using an electronic mail message |
| Feb-24-2004 |
A data formatting method for embedding diverse data types in an electronic mail message includes the step of forming a network compliant electronic mail message header. Command blocks representing diverse... |
| 5058159 |
Method and system for scrambling and descrambling audio information signals |
| Oct-15-1991 |
Audio signals are scrambled by inverting the original; frequency spectrum so that frequency portions originally lying at the lower end of the audio frequency band are shifted to the upper end while those... |
| 4586081 |
Method and apparatus for secure audio channel transmission in a CATV system |
| Apr-29-1986 |
A secure audio channel transmission system method and apparatus in which an FM signal is generated on an FM broadcast frequency, such as 107.5 megahertz, divided in frequency by 2 and distributed via a... |
| 5471531 |
Method and apparatus for low cost audio scrambling and descrambling |
| Nov-28-1995 |
Audio signals are descrambled by double sideband modulating the scrambled audio signal with a modulation carrier having a carrier frequency slightly above the highest audio signal present in the scrambled... |
| 4148063 |
Method and apparatus for encoding audio signals in television systems |
| Apr-3-1979 |
At the television transmitting end, the program audio signals to be encoded are limited to a range of 50 to 7,500 Hz. A 202 KHz signal is modulated by the so-limited audio signal and the resultant upper... |
| 5598471 |
Method and apparatus for encoding and decoding of audio transmission signals |
| Jan-28-1997 |
A system for encoding and decoding an audio transmission signal comprises: (a) an encoder with a frequency-varying means to vary the carrier frequency of the audio signal according to an encryption algorithm;... |
| 6061793 |
Method and apparatus for embedding data, including watermarks, in human perceptible sounds |
| May-9-2000 |
A technique for hiding of data, including watermarks, in human-perceptible sounds, that is, audio host data, is disclosed. In one embodiment a method comprises three steps. In the first step, data to be... |
| 5206908 |
Method and apparatus for detecting timing pulses for scrambled television system |
| Apr-27-1993 |
A method and apparatus for detecting timing pulses for descrambling a scrambled television signal, wherein a video IF signal and a sound IF signal are separated from a scrambled television IF signal by... |
| 4581765 |
Information security system |
| Apr-8-1986 |
A system is disclosed for encoding and decoding the audio signal portion of a television signal to prevent unauthorized reception of the audio signal. At the encoding stage, the audio signal is applied... |
| 5528692 |
Frequency inversion scrambler with integrated high-pass filter having autozero to remove internal DC offset |
| Jun-18-1996 |
A frequency inversion scrambler in a cordless telephone utilizes an integrated high-pass filter (14) between a first stage low-pass filter (12) and modulator (16) to reduce the filter order while maintaining... |
| 4659875 |
Electronic system for the secret transmission of audio signals |
| Apr-21-1987 |
System for the secret transmission of audio signals having at one end a coding arrangement comprising an input low-pass filter which selects the secret audio signals to be transmitted, two parallel signal... |
| 4636853 |
Dynamic audio scrambling system |
| Jan-13-1987 |
A multi-mode audio scrambling system includes an all-pass filter and a 90 degree phase shift circuit for supplying balanced modulators with 90 degree phase displaced audio information and 90 degree phase... |
| 5144666 |
Decoder to decode an encrypted sound |
| Sep-1-1992 |
Decoder for encrypted sound signals which are encrypted by modulating the sound signals on an alternating carrier signal having a frequency which is generally unknown to receiving parties. A modulator... |
| 7043019 |
Copy protection for digital motion picture image data |
| May-9-2006 |
An apparatus and method for displaying a copy-deterrent pattern (104) within a digital motion picture in order to discourage recording of the motion picture using a video camera or other sampling recording... |
| 6424925 |
Circuit and method for detecting a tone signal |
| Jul-23-2002 |
A tone detector includes at least one circuit (hereinafter "single phase reference matcher") that not only performs a convolution of an input signal with a reference signal, but also compares the result... |
| 5159631 |
Audio scrambling system using in-band carrier |
| Oct-27-1992 |
Audio signals are scrambled by single side band modulating with a modulation signal carrier having a frequency lying within the audio frequency band so that the signals are frequency translated upward.... |
| 4638357 |
Audio scrambler |
| Jan-20-1987 |
A method and apparatus are disclosed for scrambling and descrambling an audio signal. An interference signal is generated and is intermittently, preferably pseudo-randomly, added to the program audio as... |
| 4329711 |
Apparatus for encoding of information |
| May-11-1982 |
Information encoding apparatus comprises at least two modulators, each operating on a different channel, means for combining the outputs of the modulators, means for applying an information signal to the... |
| 6427012 |
Apparatus and method for embedding and extracting information in analog signals using replica modulation |
| Jul-30-2002 |
Apparatus and methods are provided for embedding or encoding auxiliary signals into an analog host or cover signal. A replica of the cover signal or a portion of the cover signal in a particular domain... |
| 6683958 |
Apparatus and method for embedding and extracting information in analog signals using distributed signal features and replica modulation |
| Jan-27-2004 |
Apparatus and methods are provided for embedding or embedding digital data into an analog host or cover signal. A distributed signal feature of the cover signal in a particular domain (time, frequency... |
