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7613298 System and process for adaptive and progressive scrambling of video streams  
A process for distributing digital video sequences in accordance with a nominal stream format including a succession of frames, each frame including at least one digital block regrouping a...
7602908 System and method for using a streaming protocol  
An initialization vector (IV) is employed to decrypt a block of a stream that has been encrypted with Cypher Block Chaining (CBC) encryption, without requiring decryption of previous blocks within...
7502463 Methods and apparatus for implementing a cryptography engine  
Methods and apparatus are provided for implementing a cryptography engine for cryptography processing. A variety of techniques are described. A cryptography engine such as a DES engine can be...
7298840 Method and system for data integrity protection  
A method of authenticating a message ( 111 ) received via a transmission channel ( 108 ) using a Message Authentication Code (MAC). The message comprises a message body ( 114 ) and a tag ( 116 )...
7260217 Speculative execution for data ciphering operations  
In one embodiment, a computer-implemented method comprises receiving a data cipher operation. The method also comprises processing the data cipher operation. The processing of the operation...
7246235 Time varying presentation of items based on a key hash  
A method for key verification through time varying item presentation based on a key hash result comprises generating a key hash result partially based on both a global identifier provided from a...
7155011 Encryption method, decryption method, and recording and reproducing apparatus  
The present invention relates to an encryption method for encrypting information including a series of multiple unit blocks, one at a time, a decryption method for decrypting multiple encrypted...
7142671 Methods and apparatus for implementing a cryptography engine  
Methods and apparatus are provided for implementing a cryptography engine for cryptography processing. A variety of techniques are described. A cryptography engine such as a DES engine can be...
7124442 System and method for insertion and retrieval of microthreads in transmitted data  
A system for the insertion of microthreads in transmitted data is provided. The system includes a digital content system providing carrier data, such as sampled audio data. A microthread insertion...
7076060 Cipher  
A cipher for enciphering and deciphering a signal includes a plurality of sequentially coupled cipher units, each cipher unit being operable to carry out a reversible operation on the signal. The...
7062651 Network printer registration protocol  
In a network connected to a printer and a registration server, a network registration protocol for registering the printer on the network includes the steps of installing a secret unique identifier...
7058178 Synchronous stream cipher  
A synchronous data-stream generator, suitable for use as a synchronous stream cipher providing copy right protection for audio/video data, generates a stream of output data items in synchronisation...
7051203 Data watermarks created by using an uneven sampling period  
Input signals are electronically watermarked using an uneven or non-uniform sampling rate. The uneven or non-uniform sampling may be pseudo-random. The uneven or non-uniform sampling meets the...
6970561 Encryption and decryption with endurance to cryptanalysis  
An encrypting apparatus includes an encrypting operation section, a determining section and a control section. The encrypting operation section carries out an encrypting operation to a plaintext...
6393126 System and methods for generating trusted and authenticatable time stamps for electronic documents  
A trusted time infrastructure system provides time stamps for electronic documents from a local source. The system comprises a trusted master clock, a trusted local clock, and a network operations...
6320965 Secure watermark method and apparatus for digital signals  
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...
6249583 On-line signal processing method  
A method for encryption and decryption of analog signal, wherein encryption and decryption are performed in analog domain. The transmitter creating digital representations with unique behavior;...
6182214 Exchanging a secret over an unreliable network  
Threshold cryptography (secret sharing) is used for exchanging a secret between a server and a client over an unreliable network. Specifically, a secret is computationally divided into N shares...
6032258 Apparatus and methods for transmission security in a computer network  
A method for validating a message packet communicated from a source node to a destination node in a computer network is disclosed. The source node and destination node have access to a clock...
5999566 Method and apparatus for providing error-tolerant communication of information  
The device and method according to the present invention permute the order of signals representing information intended for transmission over a communication medium. The signal ordering is permuted...
5933431 Frame-based modulus interleaver  
The frame based modulus interleaver is used in a digital communications system. The interleaver uses an algorithm which insures that all of the data blocks which are present in the each input frame...
5892899 Tamper resistant methods and apparatus  
In accordance with a first aspect of the present invention, a security sensitive program that operates with a secret is made tamper resistant by distributing the secret in space as well as in time....
5892775 Method and apparatus for providing error-tolerant storage of information  
The device and method according to the present invention permute the order of signals representing information intended for storage in a memory. The signal ordering is permuted prior to or at the...
5818934 Method and apparatus for providing a cryptographically secure interface between the decryption engine and the system decoder of a digital television receiver  
A method for providing a secure interface between a decryption engine and a system decoder of a digital receiver, e.g., an MPEG-2 digital television receiver. The system decoder receives an...
5535275 Apparatus and method for producing scrambled digital video signals  
Unauthorized copying of a video signal is prevented by means of a compression encoding circuit that selectively applies scrambling to the encoded signal. The compression encoding circuit is of the...
5335275 Television scrambler  
A video encryption/decryption system in which lines of video information are stored in digitised form in a block of RAM memory, and are typically shuffled in groups of 32 lines by pivot reading...
5303302 Network packet receiver with buffer logic for reassembling interleaved data packets  
A network controller receives encrypted data packets in the form of interleaved streams of cells, and stores the received cells in a buffer until the end of each packet is received, at which time...
5253296 System for resisting interception of information  
A time segment scrambling information encoding and decoding system wherein a multiplicity of scrambling algorithms are stored in a memory such as a ROM for use during transmission via a chosen...
5208857 Method and device for scrambling-unscrambling digital image data  
A method and device are disclosed for scrambling-unscrambling digital image data. The data is subjected to processing for extracting the colorimetric components of the pixels forming the image, the...
5206906 Video scrambling system  
At least one new video signal is created by using portions taken from each signal of a plurality of original video signals to create at least one new video signal, with the sequencing of the...
5161191 Encryption system for time division multiplexed networks  
An encryption system is provided for interfacing a time division multiplexing (TDM) telecommunications arrangement with an encryption device for the scrambling of data received by the...
4965827 Authenticator  
An authenticator for digital data is derived by generating a numerical array, using a secret key to controllably shift the relative positions of the elements of the array, and applying the...
4937867 Variable time inversion algorithm controlled system for multi-level speech security  
A method for scrambling speech such as in a mobile land based communication system is disclosed. Essentially, variable length time samples of digitized speech are stored and time inversion...
4905278 Scrambling of analogue electrical signals  
In a system in which an audio signal is scrambled by being divided into blocks each comprising a plurality of segments, and the segments are re-ordered within the blocks to provide the scrambled...
4852166 Analogue scrambling system with dynamic band permutation  
An analogue scrambling system with dynamic band permutation in which the speech signal is filtered (1), sampled (2) at the rate f e , digitized (3), transformed by means of an analysis filter bank...
4827513 Communications system  
A communications scrambler operates on a digital basis in which digital or digitized incoming and outgoing signals are merged (60) into a single bit stream for application to a binary bit store...
4811394 Variable starting state scrambling circuit  
PN sequence generators used in the scrambling and descrambling circuits at remote locations are periodically preset to the same value in order to maintain synchronism, with the preset value being...
4773092 Speech scramblers  
A band scrambler which processes only time domain samples is described. The band scrambler has the effect of dividing the input signal spectrum into N sub-bands. The N sub-bands are permuted such...
4771455 Scrambling apparatus  
The present invention relates to a scrambling apparatus and particularly to a scrambling apparatus in which a scrambling signal is inserted into a main signal in a predetermined period (period of...
4750205 Frequency or time domain speech scrambling technique and system which does not require any frame synchronization  
The present invention relates to speech scrambling techniques and systems and in particular to a frequency or time domain speech scrambling technique and system which does not require any frame...
4731839 Method for coding and de-coding audio and video information  
There is described a method for coding and de-coding in an information-transmission system, particularly for pay-television, which comprises for coding, converting the input analog signal into a...
4683586 Scrambling system for an audio frequency signal  
A scrambling system for an audio frequency signal is disclosed which employs a timebase-compressing and/or expanding system to measure the compressed and/or expanded amount of a segment time length...
4600941 Scrambling system for audio frequency signals  
A scrambling system for an audio frequency signal in which an audio signal is divided into blocks, each block being formed of a plurality of frames, the plurality of frames are rearranged on a...
4598169 System for detecting a marker signal inserted in an information signal  
A system for detecting a marker signal with a predetermined pattern inserted periodically in an information signal comprises a circuit which repetitively generates window signals and successively...
4551580 Time-frequency scrambler  
Subband signals are formed each corresponding to a portion of an input signal frequency spectrum. The subband signals are partitioned into subband time segments. The subband time segment signals...
4547802 TV Scrambler/descrambler using serial memories  
Apparatus for scrambling and descrambling the video portion of TV signals is disclosed. The video portion of the TV signal is stored in a serial memory such as a charge coupled device. Scrambling...
4459611 Image conversion system  
The image converting system including an image input step or apparatus for converting an original document information into electric image signals an inputting them, an image processing step or...
4443660 System and method for encrypting a voice signal  
A system and method are disclosed for encrypting a voice signal. The input signal is filtered to provide a signal in a first path with components in a higher frequency band and a signal in a second...
4433211 Privacy communication system employing time/frequency transformation  
A privacy communication system digitizes a voice signal and divides the signal into different frequency bands or time segments and shifts the bands or segments in frequency and/or time under...
4405942 Method and system for secure transmission and reception of video information, particularly for television  
A method and a system for secure transmission and reception of a video signal wherein parts of the video signal arranged in a first predetermined sequence are delayed in relation to each other to...
Matches 1 - 50 out of 77 1 2 >