Abstract: A method and device for preventing video tape piracy of video material shown by an electronic projector by varying frequently the frame rate, line rate or pixel rate of the projector. In a preferred embodiment the frame rate is varied in accordance with a cryptographically secure algorithm. In another embodiment the frame rate is varied in accordance with the content of the scene in the film.

Abstract: Various improvements to steganographic systems, and applications therefore, are disclosed. Among these are analyzing content data (e.g., audio, image data) in a computer memory automatically, without user intervention, so as to detect steganographically embedded information. The results of such analysis can be used to alter an aspect of the computer device's operation with respect to such content data. One application of the technology is to check the “clipboard” of a computer and alert the user when copyrighted material is found therein.

Abstract: A digital watermark embedding device and method uses block correlation to perform motion detection on temporally sequential digital video signals after performing preprocessing such as division into blocks. The device and method evaluate a plurality of motion information which are calculated for blocks by using a technique such as determination by majority or weighting. Based on the detected motion information, by moving a digital watermark pattern to follow a picture, the digital watermark information can be superimposed on an input digital video signal so as to match human visual characteristics by using a technique such as emphasizing a portion on which the human eye is easily turned.

Abstract: The invention relates to a watermark embedding method and to transcoding and digital recording apparatus including a facility for watermark embedding. A first embodiment incorporates a watermark embedding system with a cascaded decoder/encoder transcoder of the type commonly found in digital recording apparatuses. An input data stream in a first format is received by a decoder (10) of the transcoder. Coding parameters are fed from a first output of the decoder (10) to a first input of an encoder (30) of the transcoder. A second output of the decoder (10) comprises a baseband video signal which is passed to a first input of an adder (24). An output of a watermark generator (22) is fed to a second input of the adder (24). An output of the adder (24) is fed to a second input of the encoder 30. The output of the encoder (30) comprises the information to be recorded in a second format which is compatible with a storage medium.

Abstract: The invention relates to a process for scrambling video data in the MPEG2 video format as well as to a process for descrambling data scrambled according to the process of the invention. The scrambled video data are the coefficients AC and/or DC arising from the “discrete cosine transform” operation which are associated with at least one block of at least one image coded in INTRA mode. The invention applies to conditional access systems such as, for example, pay television systems.

Abstract: Electronic steganographic techniques can be used to encode a rights management control signal onto an information signal carried over an insecure communications channel. Steganographic techniques ensure that the digital control information is substantially invisibly and substantially indelibly carried by the information signal. These techniques can provide end-to-end rights management protection of an information signal irrespective of transformations between analog and digital. An electronic appliance can recover the control information and use it for electronic rights management to provide compatibility with a Virtual Distribution Environment. In one example, the system encodes low data rate pointers within high bandwidth time periods of the content signal to improve overall control information read/seek times.

Abstract: The invention relates to a method of embedding a secondary signal of a secondary channel in the bitstream of a primary signal of a primary channel. For copy protection and digital rights management for recordable or rewritable data carriers it is required that a key can be written and rewritten in a hidden side channel, i.e. in the secondary channel. Therefore it is proposed according to the invention that the bitstream of the primary signal is distorted before outputting the bitstream of the primary signal such that the secondary signal is represented by a predetermined distortion. The invention relates further to a method for detecting a secondary signal embedded in the bitstream of a primary signal, to corresponding apparatuses and to a corresponding data carrier.

Abstract: In the apparatus and method for a watermark embedding and detection through a linear prediction analysis, and a record medium capable of being read through a computer having a writing of a program to realize the inventive method, in which a quality of a signal does not drop, even after an imbedding of a watermark by using a signal based on a changed shape of an original signal through a use of a linear prediction analysis, with a watermark signal to be imbedded in a digital signal, but also the watermark signal containing copyright information can be detected even though an optional attack is applied thereto.

Abstract: The invention allows the introduction in real-time of at least sufficient security to minimize the risk of intruders overhearing data on a particular link. This reduces the risk of being victim to either a Type 1—Unauthorized access threat or a Type 3—Message sequencing threat. The method involves encryption at the physical data link level where the form of the encryption affects groups of data bits. The effect of introducing the invention is to add noise to the signal in such a way that it can be subtracted from the received signal leaving only the original signal. The resulting signal, were it to be observed by a person other than the intended recipient, would have an effective Signal to Noise (S/N) ratio of less than 1. The masking effect of this added ‘noise’ signal hides the original signal from any eavesdroppers, since it well-known in the art that for a non-periodic signal to be effectively recovered it must have a S/N greater than 1.

Abstract: A system and method for preventing the illicit copying and processing of digital recordings. In particular, the system inhibits the merging or stitching together of fragments of a digital recording in order to defeat a protection scheme. To accomplish this, the invention provides a compliant device having a system for merging digital recordings and which comprises a system for receiving a first digital recording and a second digital recording; and a system for merging the first digital recording and the second digital recording into an output, wherein the output includes a disruption between the first digital recording and the second digital recording. Attempts at recording stitched together fragments will thus result in an outputted recording having disruptions, which will cause frequent interruptions or loudness fluctuations during playback.

Abstract: In order to descramble sections of scrambled data interleaved with sections of unscrambled data in a transport stream of broadcast video data, while leaving the sections with the original timing relationship in the transport stream, a common data flow path (1-5) is provided both for sections of scrambled data and sections of unscrambled data and signal path loops (6,7; 8,9) including cipher means (62,64) to enable the descrambling of scrambled data, and a control state machine for controlling the flow of data through said common data flow path and said signal path loops to enable passage of unscrambled data sections and descrambling of scrambled data sections, while maintaining the desired relative positions of the data sections.

Abstract: A system for broadcasting data signals in a secure manner comprises means for encrypting the data signals using a first key, means for broadcasting the encrypted data signals to subscribers, means for decrypting the encrypted data signals at each of the subscribers using the first key, and means for encrypting the first key using a second key. The second key is different for each group of subscribers having a common interest in a type of programs. The system further comprises means for broadcasting the encrypted first key to all subscribers and means for decrypting the encrypted first key at each of the subscribers using the second key. The second key is a combination of a key common to all subscribers and a difference key which is unique per type of programs. Means are provided for encrypting the common key and for broadcasting the encrypted common key to all subscribers, the subscribers having means for decrypting the encrypted common key at each of the subscribers.

Abstract: In a method for providing a secure communication between two devices, a first device generates a random key (Ci) and transfers this key to a second device in a first message encrypted using a public key. The second device decrypts the first encrypted message by means of a corresponding secret key to obtain the random key (Ci) and this random key is used to encrypt and decrypt all transmissions between these devices. In a decoder for a pay TV system, comprising a conditional access module and a smart card, this method is applied to provide a secure communication between the control access module and the smart card and/or between the decoder and the conditional access module.

Abstract: Watermark data is encoded in a digitized signal by forming a noise threshold spectrum which represents a maximum amount of imperceptible noise, spread-spectrum chipping the noise threshold spectrum with a relatively endless stream of pseudo-random bits to form a basis signal, dividing the basis signal into segments, and filtering the segments to smooth segment boundaries. The data encoded in the watermark signal is precoded to make the watermark data inversion robust and is convolutional encoded to further increase the likelihood that the watermark data will subsequently be retrievable notwithstanding lossy processing of the watermarked signal.

Abstract: A wireless communications system (110) with increased privacy. The system (110) transmits an encrypted signal between a base station (112) and a wireless terminal (122). In the forward channel, the base station (112) includes an encryptor (130) with a long code mask generator (200) that generates a rolling long code mask. The wireless terminal (122) similarly includes a decryptor (164) with a long code mask generator (208) that creates a rolling long code mask.

Abstract: Watermark data is encoded in a digitized signal by forming a noise threshold spectrum which represents a maximum amount of imperceptible noise, spread-spectrum chipping the noise threshold spectrum with a relatively endless stream of pseudo-random bits to form a basis signal, dividing the basis signal into segments, and filtering the segments to smooth segment boundaries. The data encoded in the watermark signal is precoded to make the watermark data inversion robust and is convolutional encoded to further increase the likelihood that the watermark data will subsequently be retrievable notwithstanding lossy processing of the watermarked signal. To produce the endless pseudo-random bit stream, subsequent bits of the sequence are generated in a pseudo-random manner from previous bits of the sequence. The pseudo-random bits are appended to the stream of pseudo-random bits and, additionally, replace a number of bits of the state.

Abstract: Electronic steganographic techniques can be used to encode a rights management control signal onto an information signal carried over an insecure communications channel. Steganographic techniques ensure that the digital control information is substantially invisibly and substantially indelibly carried by the information signal. These techniques can provide end-to-end rights management protection of an information signal irrespective of transformations between analog and digital. An electronic appliance can recover the control information and use it for electronic rights management to provide compatibility with a Virtual Distribution Environment. In one example, the system encodes low data rate pointers within high bandwidth time periods of the content signal to improve overall control information read/seek times.

Abstract: A method of hiding copyright related messages within digital data works is taught. The method relies on modifying data elements in the work according to certain rules which depend on the actual message itself. The information content of the message can be extracted through a comparison of measurable characteristics of defined portions of the modified work.

Abstract: In an electronic watermark detecting/inserting device which includes an electronic watermark detecting section (30) for detecting a first electronic watermark from a first DCT coefficient of an input digital image to produce a request for insertion of a second electronic watermark and an electronic watermark inserting section (20) for producing, in response to the request for insertion of the second electronic watermark, an output digital image which includes the first electronic watermark inserted therein and the second electronic watermark inserted subsequently to the first electronic watermark in the output digital image and which has the second DCT coefficient, a second DCT coefficient producing section (40) produces the second DCT coefficient from the output digital image. A DCT coefficient supplying section (50) supplies the second DCT coefficient from the second DCT coefficient producing section to the electronic watermark detecting section.

Abstract: Electronic steganographic techniques can be used to encode a rights management control signal onto an information signal carried over an insecure communications channel. Steganographic techniques ensure that the digital control information is substantially invisibly and substantially indelibly carried by the information signal. These techniques can provide end-to-end rights management protection of an information signal irrespective of transformations between analog and digital. An electronic appliance can recover the control information and use it for electronic rights management to provide compatibility with a Virtual Distribution Environment. In one example, the system encodes low data rate pointers within high bandwidth time periods of the content signal to improve overall control information read/seek times.

Abstract: A novel method and apparatus for scrambling a television signal includes using a synchronization separator to separate a synchronization signal from an input audio-visual signal. The synchronization signal is then used to regulate an oscillator producing an audio carrier signal. In this manner, the audio-visual signal is transmitted without the component synchronization signal rendering it useless to a conventional television receiver. The descrambler and descrambling method of the invention involve removing the audio carrier signal from the scrambled signal and using the audio carrier signal to generate the color sub-carrier signal and a vertical time frame reference signal necessary to synchronize the transmitted audio visual signal for display.

Abstract: An audio input interface (122) receives a digital audio signal and identifies an audio bitstream which is optionally decrypted by a decryption unit (123), and decoded by an audio decoding unit (124). An audio digital to analog converter (126) converts the decoded audio bitstream to an analog audio signal which is optionally decrypted by an audio analog decryption unit (127). A video input interface (142) receives a digital video signal and identifies a video bitstream which is optionally decrypted by a video digital decryption unit (143), and decoded by a video decoding unit (144). A video digital to analog converter (146) converts the decoded video bitstream to an analog video signal that is optionally decrypted by a video analog decryption unit (147). An analog transmitter (150) mixes the analog audio signal and analog video signal and transmits an analog output signal to a television (110).

Abstract: Apparatus and methods are provided for embedding watermark information into a cover signal, such as an audio signal, video signal, or still image signal, in a manner that prevents the watermark information from being removed without degrading the quality of the cover signal. This is accomplished by subjecting the cover signal to a phase modulation prior to being embedded with the watermark information, wherein the amount or degree of phase modulation is changed at least for each different watermark to be embedded in a particular instance or copy of the cover signal. As such, if two copies of the same cover signal, each containing a different watermark, are averaged or combined in an attempt to obliterate the watermark information, the cover signal will be subjected to phase cancellation, rendering any illicit copy of such signal so derived to be valueless.

Abstract: A secret data management apparatus includes an image display unit which displays an image on a display monitor. A position/sequence input unit inputs positions of input image points on the image using an input device and inputs a sequence of the positions using the input device. An encryption unit generates encrypted data of a secret key based on the positions and the sequence from the position/sequence input unit. A secret data storage unit stores the encrypted data of the secret key from the encryption unit in a storage medium. An access allowance unit allows access to the secret key stored in the storage medium when positions of input image points on the image and a sequence of the positions, subsequently specified using the input device at a time of the access, match with the positions and the sequence from the position/sequence input unit. A decryption unit generates plain data of the secret key from the encrypted data stored in the storage medium when the access is allowed by the access allowance unit.

Abstract: In a system for jamming television programs in a cable television system, modified oscillators are used to provide jamming signals to control ports where they are added to the video signal, in order to prevent unauthorized viewing. The oscillators have switchable portions so that they, when receiving appropriate control signals from a control unit on control lines, can be switched to different basic oscillation frequencies and thus each one can cover a very wide frequency range. The basic oscillation frequency of the oscillators is finely adjusted by means of a continuous signal on a line like the conventional voltage control of oscillators. The use of such switched oscillators in an interdiction apparatus for a cable television system provides a number of advantages, such as making the system more flexible and more efficient in terms of jamming capacity for more expensive programs, pay channels, needed oscillator circuitry, etc.

Abstract: An apparatus and process for hiding the secondary image within the primary image and generating a high quality hard copy of the unified elemental image of a variety of media. The process comprises the steps of rasterizing the first image into an first elemental image and rasterizing the second image, compensated with its own inverse, into an second elemental image. The first elemental image and the second elemental image are merged into a unified elemental image based on a predetermined decoding and compensating principle, resulting in the second elemental image being hidden within the first elemental image. An output image is created based on the unified elemental image where the primary image is visible to an un-aided eye while the secondary image is hidden from the un-aided eye.

Abstract: A technique is disclosed for preventing unauthorized playback of scrambled video/audio signals recorded on, for example, a video tape cassette, which technique includes several cooperating processes and apparatus which further prevent the playback of recorded video/audio when the playback apparatus is in a still or pause mode of operation. The technique includes selected combinations of processes of inverting and re-clamping the luminance component of the video signal just prior to FM modulation; blanking an overscan portion, or portions, of the video signal and adding a video retrace signal to the overscan portion(s); inverting the normal control track signal and position modulating the normally unused edge; and selectively scrambling the audio signal and recording the scrambled audio signal in an audio track or in a Hi-Fi track. A selected user specific authorization code is recording in and recovered from the audio track.