Abstract: Embodiments of wireless display of digital content include transmission using a television transmission standard, such as a set of standards defined by the Advanced Television Systems Committee (ATSC) for digital television (TV) transmissions. The digital content is transmitted in a short range wireless network. In some embodiments, an encryption technique is applied to add security allowing decryption by a digital television using a firmware update, allowing retrofitting of security to devices currently deployed.

Abstract: A method of segregating a hybrid fiber cable network involves assigning a packet identifier (PID) to each of a plurality of hubs on the hybrid fiber cable network; assigning a distinct decryption method to each of the plurality of hubs, so that each of the plurality of hubs is identifiable by its associated decryption method and PID; generating selectively multiple encrypted content for transmission to the hubs, where content encrypted for use by each hub is identified by the hub's assigned PID; and transmitting the selectively multiple encrypted content over the hybrid fiber cable network to the plurality of hubs. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.

Abstract: A system for implementing the virtual channel service generates an content key associated with each of the video on-demand (VOD) program contents for the each VOD program content multicast on a virtual channel, encrypts the VOD program contents by using the content key and multicasts the encrypted VOD program content on the virtual channel; generates a channel key for the virtual channel that multicasts the VOD program content, encrypts the content key and generates encryption information by using the channel key, and authorizes a user terminal that orders the virtual channel to the channel key, and multicasts the encryption information on the virtual channel. The user terminal that joins the virtual channel decrypts and obtains the content key by using the authorized channel key and then uses the content key to decrypt the encrypted content of the VOD program.

Abstract: A method for communicating data, such as audio/video (AV) data, over plural channels involves selecting data and encryption information, and encrypting the data with the encryption information to thereby produce encrypted data. The encryption information is broken into portions. The encrypted data is communicated by way of at least one of the plural channels, and at least some portions of the encryption information are communicated over at least one channel other than that one over which the encrypted data is communicated. In a more general case, the encrypted data is sent over one channel, and the encryption information is divided and sent over several other channels.

Abstract: During the export processing for the video content (S107), the content receiving terminal causes an encryption key for content stored in the recording medium, to be present in the content receiving terminal (S103, S105, and S106). Only when the export processing is completed or when suspension processing is normally performed, the content receiving terminal writes the content encryption key in the recording medium (S111 and S112). When the export processing is abnormally suspended, since the content encryption key is not stored in the recording medium, the other video reproducing terminals cannot reproduce the video content for which the export is incomplete.

Abstract: Apparatuses and methods may include creating at least one of a scramble key and a descramble key using a Copy Protection (CP) key that existed prior to a refresh period and using a value created at a time associated with the changing of a channel during the refresh period, and using the at least one of the scramble key and the descrambled key until the CP key is refreshed at an end of the refresh period.

Abstract: A data converting apparatus includes a segmenting unit for setting a predetermined access unit, as an access unit to be processed, out of input data containing at least one access unit containing a plurality of data components per pixel, and for segmenting the access unit to be processed into at least one block; an analyzing unit for generating a basis for converting an expression format of each of the plurality of data components by respectively setting, as at least one analysis block, at least one segmented block and for performing a main component analysis on the plurality of data components; and a converting unit for converting the expression format of each of the plurality of data components per pixel forming the block to be processed.

Abstract: A system and a method for providing variable security mechanisms for securing digital content, in which a single security mechanism is not used for all content. Instead, at least one characteristic or feature of the security mechanism is varied between units, instances or categories of content. Therefore, even if unauthorized access is gained to a single unit of content, the overall integrity and security of the system for content distribution is not compromised. Preferably, security is provided though a general mechanism, which is then varied in order to provide variable, dissimilar security schemes for different types of content. By “type of content”, it is meant any of a single unit of content, a single instance of content or a single category of content. For example, for a category of content, the content may be characterized according to the identity of the content itself, such as the title of a movie for example, and/or according to the owner of a particular copy of the content.

Abstract: According to one embodiment of the invention, the descrambler IC comprises a local memory to store a unique key and a plurality of process blocks. A first process block performs cryptographic operations on a first mating key generator using the unique key in order to produce a first key. A second process block uses the first key to perform cryptographic operations on a second mating key generator in order to produce a second key. Using the first key and the second key, a third process block decrypts a first encrypted descrambling key in order to recover a first descrambling key and a fourth process block decrypts a second encrypted descrambling key to recover a second descrambling key. The descrambler IC includes a descrambler to descramble the scrambled digital content using both the first descrambling key and the second descrambling key in order to produce digital content in a clear format.

Abstract: In a procedure for delivering streaming media, a Client first requests the media from an Order Server. The Order Server authenticates the Client and sends a ticket to the Client. Then, the Client sends the ticket to a Streaming Server. The Streaming Server checks the ticket for validity and if found valid encrypts the streaming data using a standardized real-time protocol such as the SRTP and transmits the encrypted data to the Client. The Client receives the data and decrypts them. Copyrighted material adapted to streaming can be securely delivered to the Client. The robust protocol used is very well suited for in particular wireless clients and similar devices having a low capacity such as cellular telephones and PDAs.

Abstract: The invention refers to a method of updating a multi-operator reception system by administration (EMM) and updating messages between a subscriber management system and one or several decoders of pay television, being the functioning of the decoder dependent on the reception of administration (EMM) and updating messages of at least one preferential operator, this decoder having to pass into stand-by state under certain conditions. If the subscriber uses mostly an operator that does not require subscription rights, the decoder does not receive any more the necessary updating. To switch this decoder into the stand-by state, the method according to the invention carries out the following operations: switching of the reception to one or several preferential operators, receiving and processing of the messages of management of rights (EMM), determining of the end of a complete cycle of reception messages, switching to the stand-by state.

Abstract: The invention proposes to divide a content to be transmitted via a network into a set of slices and to generate a set of files from this set of slices. The slices (or the files) are encrypted before downloading in such a way that the client cannot use the slice (or the file) before having acquired the associated decryption key. The invention thereby allows protecting a downloaded content on a slice-by-slice basis (or on a file-by-file basis) rather than protecting a downloaded content as a whole. The transmission (in download mode) between the server and the client is ruled by the HTTP protocol that is accepted by all firewalls and NAT. Consequently, the transmitted content is accessible for any client device that has access to the Web without restriction. Advantageously, the slices can be decoded independently of each other.

Abstract: A digital cinema anti-piracy system includes a modulator configured to convert an input signal to a desired disruptive frequency and to analyze a brightness, B, of each input pixel in an input frame of the signal, the modulator for determining at least the amount of brightness Bj of each pixel to be displayed in each frame j of a set of N frames, wherein the average of all the brightness values Bj in the N set of frames is substantially equal to B, and N is substantially equal to the number of frames output for each input frame. A brightness of a pixel in a second region Bf(j) can be displayed ‘out of phase’ with the brightness Bj to create a disruptive effect which is distinguishable from the first flicker effect.

Abstract: A method of setting up a secure IPTV session. An Application Server (AS) receives an invite message from an IPTV receiving node such as a mobile telephone or a Set Top Box to set up an IPTV session. The invite message includes a Bootstrapping Transaction Identifier (BTID) associated with the IPTV receiving node. The AS sends an authentication request including the BTID to a Bootstrapping Server Function (BSF). The AS then receives from the BSF, an authentication response, which includes a long-term key associated with and previously provided to the IPTV receiving node. The AS then sends a request identifying the receiving node to an IPTV content provider. The AS then uses the long-term key to encrypt a media encryption key that is used to encrypt the media sent by the content provider, and sends the encrypted media encryption key to the IPTV receiving node in an invite response.

Abstract: An object of the present invention is to prevent illegal use of data (digital contents), and a second object is to provide a method for processing data which ensures the collection of charges for secondary use of the data, a data reading method for reading the data processed by this processing method, and a recording medium storing programs implementing these methods. The method for processing data is such that in a method for processing a data body b which is encrypted and is decrypted on a decryption bit length basis, and thereby is reproduced, the data body b is encrypted, a part of this data body b with a bit length different from the decryption bit length is omitted, and the omitted part is closed so as to make the data continuous.

Abstract: Method and system of transferring scrambled content from location to another. The method and system may include transferring the scrambled content without requiring the descrambling thereof. The method and system may be used to transfer live content, stored content, and the like. The content may relate to television programming and signaling, data, still images, audio, and the like.

Abstract: The invention provides techniques to implement unique identifier for an integrated chip and how this ID can be employed to enhance the security of content in personal video recorder type systems. The storage device can be a hard disk, a removable storage medium or any other type of storage medium. An integrated circuit (IC) within the personal video recorder stores a unique identifier that is used in for encryption and decryption of data stored on the storage device. Several embodiments are disclosed herein that maintain the secrecy of the unique ID such that it is not easily accessible thereby defeating the security scheme.

Abstract: A method and apparatus are disclosed for efficiently scrambling one or more bytes of data according to DSL standards on a processor. This is achieved by providing an instruction for scrambling one or more bytes of data according to the DSL standards. Accordingly, the invention advantageously provides a processor with the ability to scramble data with a single instruction thus allowing for more efficient and faster scrambling operations for subsequent modulation and transmission.

Abstract: In a communication system, second encryption information is generated using first encryption information when data to be transmitted is generated. The data is encrypted using the second encryption information and third encryption information. A signal including the encrypted data and the first encryption information is generated and transmitted.

Abstract: In a subscriber television system with a host terminal, the present invention allows the identification of the individual packets from two separate MPEG transport streams that have been multiplexed together for decoding by a single external conditional access or point-of-deployment (POD) module. The decoding of individual packets from two separate MPEG transport streams supports the use of multiple tuner host terminals for such functions as picture-in-picture (PIP) program viewing and the viewing of one program while recording a second program.

Abstract: A set-top box (STB), digital video recorder (DVR), video player or other host device receives and interacts with a transcode module to provide enhanced transcoding capabilities that may be useful in placeshifting or other applications. The transcode module includes a host interface that couples to and communicates with the host device. The transcode module also includes a processor that receives an encrypted media stream from the host device via the bus interface, decrypts the encrypted media stream, transcodes the encrypted media stream to a different format, re-encrypts the transcoded stream, and provides the re-encrypted media stream to the host device via the host interface. The transcoded media content may be placeshifted to a remote player, stored at the host, or used for any other purpose.

Abstract: Disclosed is a digital broadcast reception apparatus which performs a scramble judgment by obtaining a judgment PID corresponding to PCR_PID and a judgment packet corresponding to the judgment PID and judging whether the judgment packet is obtained within a first time, subsequently by a value of tsc bit, subsequently by detecting a PES packet where payload starts and judging whether it is detected within a second time, subsequently by detecting packet_start_code_prefix and judging based on the detected value, and subsequently by a value of PES_scrambling_control.

Abstract: The invention relates to a protocol for disabling/erasing access rights to scrambled data. According to the invention, the access rights entered in an access control module comprise the following variables: right identification variable (R ID), action date variable (AD V) and right status variable (S V). The status variable can have one of three encoded values, namely enabled, disabled or erased right. The inventive protocol consists in: transmitting (A) at least one access right management message comprising the right identification variable (R IDx), the action date variable (AD Vx) and the status assignment variable (S Vx), the latter corresponding to a enabled, disabled or erased right; assigning (B) the action date (AD Vx) of the message to the action date (AD V) of the right entered; and allocating (C) the status assignment variable (S Vx) of the message, corresponding to an enabled, disabled or erased access right, to the status variable (S V) of the entered access right.

Abstract: A data processing system includes: a stream decoder for decrypting a stream encrypted by broadcast encryption to obtain a first decrypted stream; an internal buffer for storing the first decrypted stream; and an encryption/decryption processor. The encryption/decryption processor decrypts a stream encrypted by content encryption to obtain a second decrypted stream and storing the second decrypted stream in the internal buffer, and reads one of the first and second decrypted streams from the internal buffer and encrypts the read-out stream by content encryption.

Abstract: In a system, a server provides a digital signal processing function ƒ to an executing device in an obfuscated form. The function ƒ includes a function cascade of signal processing functions ƒi, 1?i?N (e.g., FC1(x)?ƒN? . . . ?ƒ1(x)). The server includes a processor for selecting a set of 2N invertible permutations pi, 1?i?2N; calculating a set of N functions gi, where gi is functionally equivalent to p2i?1?ƒi?p2i?1, for 1?i?N; and calculating a set of N?1 functions hi, where hi is functionally equivalent to p2i?1?1?p2i?2, for 2?i?N. The server equips the executing device with an execution device function cascade that includes yN?hN?yN?1?hN?1? . . . ?y1, where y1, . . . , yN are function parameters (e.g., ED1(y1, . . . , yN)?yN?hN?yN?1?hN?1? . . . ?y1), and provides the functions g1, . . . gN to the executing device. The executing device obtains the functions g1, . . .

Abstract: Consistent with embodiments of the present invention, systems and methods are disclosed for deriving a secure key.

Abstract: A method of recording scrambled digital data comprising the steps consisting in: (a) receiving a scrambled digital data stream; (b) identifying in the data stream a control packet (ECM) containing at least one key (CW) for descrambling at least a part of the data of the stream; (c) storing the control packet in a table; and (d) recording the data stream and the said table on a data storage medium. A storage medium and a method of reading the recorded data are also proposed.

Abstract: A unified system of programming communication. The system encompasses the prior art (television, radio, broadcast hardcopy, computer communications, etc.) and new user specific mass media. Within the unified system, parallel processing computer systems, each having an input (e.g., 77) controlling a plurality of computers (e.g., 205), generate and output user information at receiver stations. Under broadcast control, local computers (73, 205), combine user information selectively into prior art communications to exhibit personalized mass media programming at video monitors (202), speakers (263), printers (221), etc. At intermediate transmission stations (e.g., cable television stations), signals in network broadcasts and from local inputs (74, 77, 97, 98) cause control processors (71) and computers (73) to selectively automate connection and operation of receivers (53), recorder/players (76), computers (73), generators (82), strippers (81), etc.

Abstract: A random number or HDCP key is sent from a TV to a set back box (SBB) over a HDMI channel, and unless the SBB returns the same random number/key to the TV over a USB link, the TV will not communicate further with the SBB.

Abstract: A method for transmission and storing of scrambled content in which the scrambled content is transmitted together with encrypted control words, the control words being used for descrambling the scrambled content, transmitting to a receiver/decoder the scrambled content and encrypted control words, said control words being encrypted by an exploitation key (KG), decrypting said encrypted control words in a removable security module with an exploitation key (KG), said removable security module being received by the receiver/decoder, characterised in that it further includes transmitting usage rules message (URM) to the receiver/decoder (2000), which usage rules (URM) impose usage constraints on the playback of the content stored on a mass storage device encrypting the decrypted encrypted control words and usage rules messages by a local key (KL) to produce encrypted control management messages (CMM) storing said scrambled content and encrypted control management message on the mass storage device of the receiver

Abstract: A unified system of programming communication. The system encompasses the prior art (television, radio, broadcast hardcopy, computer communications, etc.) and new user specific mass media. Within the unified system, parallel processing computer systems, each having an input (e.g., 77) controlling a plurality of computers (e.g., 205), generate and output user information at receiver stations. Under broadcast control, local computers (73, 205), combine user information selectively into prior art communications to exhibit personalized mass media programming at video monitors (202), speakers (263), printers (221), etc. At intermediate transmission stations (e.g., cable television stations), signals in network broadcasts and from local inputs (74, 77, 97, 98) cause control processors (71) and computers (73) to selectively automate connection and operation of receivers (53), recorder/players (76), computers (73), generators (82), strippers (81), etc.

Abstract: An electronic storage device has a segment of digital video content recorded thereon as a data structure with a first set of data packets encrypted under a first encryption process and a second set of data packets encrypted under a second encryption process. The first set of video data packets and the second set of video data packets, when unencrypted, represent duplicate copies of the same video information. A third set of data packets contains unencrypted video data that is contextually contiguous to the first set of data packets and the second set of data packets. The first and third set of data packets represents all video content in the segment of digital video content as does the second and third set of data packets.

Abstract: A system 100 for updating cryptographic key data 120 comprises a key input 106 for receiving sequential key updates 114; and a key data updater 108 for changing a portion (116) of the cryptographic key data in response to a received one of the sequential key updates (114), the portion not including all the cryptographic key data, wherein different respective portions of the cryptographic key data are selected for respective ones of the sequential key updates. The system further comprises a content input 104 for receiving content data 112 to be processed; and a cryptographic unit 110 for cryptographic processing of the content data in dependence on the key data to obtain processed content data 118. The content input is arranged for receiving a content data stream, successive portions of the content data stream being encrypted based on successive keys corresponding to the successive key updates.

Abstract: An information recording and/or reproducing method for supervising the information, such as an input source, in a stream recorded on a recording medium. If, in a reproduction processing of reproducing an AV stream from the recording medium, the source_security_info, which is the copy control information recorded on the recording medium, is read out, the AV stream is read out, and analog video, for example, is output (step 203), it is verified, from the information contained in the source_security_info, whether or not the input source is DTCP-concordant. If the input source is DTCP-concordant, reproduction restricting processing for a video output, conforming to the DTCP rule, is executed to issue the video output.

Abstract: Methods and arrangements are disclosed for embedding and detecting a watermark in a cinema movie, such that the watermark can be detected in a copy made by a handheld video camera. The watermark embedder divides each image frame into two areas. A watermark bit ‘+1’ is embedded in a frame by increasing the luminance of the first part and decreasing the luminance of the second part. A watermark bit ‘?1’ is embedded by decreasing the luminance of the first part and increasing the luminance of the second part. It is achieved with the invention that the embedded watermark survives ‘de-flicker’ operations that are often used to remove flicker caused by the different frame rates of cinema projection equipment and consumer camcorders.

Abstract: A digital data false alteration detection program causes a computer to execute (a) a step (S1) of dividing digital data into a plurality of smaller block data, (b) a step (S2) of extracting noise inherent to a digital data acquisition device for each of the small block data, (c) a step (S3) of calculating correlation of the noise between adjacent small block data, and (d) a step (S4) of detecting small block data having noise correlation lower than a level predetermined for the surrounding small block data, as falsely altered data.

Abstract: Decryption apparatus includes an input memory (48), which is coupled to receive encrypted data, and an output transducer (28), for presenting decrypted data to a user. A decryption processor (50) is coupled to read and decrypt the encrypted data from the input memory but is incapable of writing to the input memory, and is coupled to convey the decrypted data to the output transducer for presentation to the user.

Abstract: A scrambling apparatus and method are provided for increasing randomness without damaging compression efficiency of total video data by selectively and randomly performing conversion when converting motion vector codes of compressed video data into other motion vector codes indicating other motion vector values, and more particularly, by performing conditional conversion only if a predetermined condition is satisfied when selective conversion of motion vector codes is performed. The scrambling apparatus includes a conversion motion vector code table generator generating a conversion motion vector code table comprising motion vector codes obtained by converting motion vector codes corresponding to motion vector values of input video data in a standard motion vector code table; and a conversion controller randomly determining whether a certain motion vector value is encoded using the conversion motion vector code table or the standard motion vector code table.

Abstract: A method and system for distribution of scrambled data and/or services to at least one master terminal and to at least one slave terminal linked with the master terminal. The method and system transmit to the master terminal a first secret code and transmit to each slave terminal a second secret code in a biunique relationship with the first secret code, and authorize the reception of the data and/or services by a slave terminal only if the first secret code is previously stored in the slave terminal.

Abstract: The invention discloses a new modulation scheme to prevent illegal copy in movie theaters. None of the existing modulation schemes make the right assumptions to modelize a camcorder device. In such classical schemes, camcorders are always considered as sampling devices without taking into account the effects of shutter speed. The shutter of the camcorder is classically compared to a low-pass filter. As a result, modulation effects can be easily removed by setting up shutter speed to low values (low cutoff frequency). The right mathematical modelization of the shutter effect shows that, in the spectral domain, the behavior of the camcorder is close to a cardinal sine function with a main lobe and sidelobes.

Abstract: A unified system of programming communication. The system encompasses the prior art (television, radio, broadcast hardcopy, computer communications, etc.) and new user specific mass media. Within the unified system, parallel processing computer systems, each having an input (e.g., 77) controlling a plurality of computers (e.g., 205), generate and output user information at receiver stations. Under broadcast control, local computers (73, 205), combine user information selectively into prior art communications to exhibit personalized mass media programming at video monitors (202), speakers (263), printers (221), etc. At intermediate transmission stations (e.g., cable television stations), signals in network broadcasts and from local inputs (74, 77, 97, 98) cause control processors (71) and computers (73) to selectively automate connection and operation of receivers (53), recorder/players (76), computers (73), generators (82), strippers (81), etc.

Abstract: The invention defines a method for leveraging the standard conditional access module interface of a digital TV receiver to deliver IPTV or other TV content without the need of a set top box. An IP-connected interface (“probe”) is used in place of a conditional access module to establish a two-way communication link between the TV and the IPTV headend or other IP content source and to deliver IP content. In an embodiment, the invention covers the specifics of content navigation without requiring any modification of the TV receiver application software or provisioning of IPTV-specific software. Content navigation is achieved by supporting a catalog/grid browsing session on the TV receiver and enabling a flat multiplex navigation, a virtual MPEG multiplex that contains the definition of several available programs but a single video and audio channel is dynamically switched to carry the selected program.

Abstract: A system includes an HDCP-over-USB controller including an HDCP module for encrypting or decrypting video data according to an HDCP standard prior to transmission or display of said video data.

Abstract: A system and methods for permitting open access to data objects and for securing data within the data objects is disclosed. According to one embodiment of the present invention, a method for securing a data object is disclosed. According to one embodiment of the present invention, a method for securing a data object is disclosed. The method includes the steps of (1) providing a data object comprising digital data and file format information; (2) embedding independent data into a data object; and (3) scrambling the data object to degrade the data object to a predetermined signal quality level. The steps of embedding and scrambling may be performed until a predetermined condition is met. The method may also include the steps of descrambling the data object to upgrade the data object to a predetermined signal quality level, and decoding the embedded independent data. The additional steps of descrambling and decoding may be performed until a predetermined condition is met.

Abstract: Apparatus and methods are provided for inserting advertisements and/or to perform grooming functions after a video, audio and/or data stream has been transrated and/or encrypted. In this manner, ad insertion and grooming can be performed close to the edge of a video distribution network. Transrating and encryption of a program into which content is to be later inserted can be accomplished before the program is transmitted. Thus, a single encrypted version of a program can be transmitted from a central point in the network to multiple recipients, while providing the benefits of subsequent targeted ad insertion or grooming downstream of the central point.

Abstract: A novel method and apparatus for protection of streamed media content is disclosed. In one aspect, the apparatus includes control means for governance of content streams or content objects, decryption means for decrypting content streams or content objects under control of the control means, and feedback means for tracking actual use of content streams or content objects. The control means may operate in accordance with rules received as part of the streamed content, or through a side-band channel. The rules may specify allowed uses of the content, including whether or not the content can be copied or transferred, and whether and under what circumstances received content may be “checked out” of one device and used in a second device. The rules may also include or specify budgets, and a requirement that audit information be collected and/or transmitted to an external server. In a different aspect, the apparatus may include a media player designed to call plugins to assist in rendering content.

Abstract: A digital broadcast receiver and a control method thereof are disclosed. The control method includes receiving a broadcast signal into which mobile service data and main service data are multiplexed, extracting TPC signaling information and FIC signaling information from a data group in the received mobile service data, acquiring a program table describing virtual channel information and a service of an ensemble, using the extracted FIC signaling information, the ensemble being a virtual channel group of the received mobile service data, detecting a conditional access descriptor indicating whether the mobile service data was encrypted, using the acquired program table, and controlling such that the encrypted mobile service data is decrypted, using information of the detected conditional access descriptor.

Abstract: A conditional access method and apparatus for use with a system for controlling of digital TV program start time. Subscriber access is authorized to digital program streams. Content are divided into a plurality of working periods. Each working period of the plurality of working periods is scrambled with a different working key. A working key of a given period is delivered ahead of the given period. The working key is synchronized with scrambling control bits in an header. working keys are inserted into an entitlement control message (ECM) packet, and the ECM packet is encrypted using a service key. A time period is inserted into the ECM packet during which the service key is valid. A service key is inserted in an entitlement.

Abstract: A security device and a head end of a conditional access system (CAS), and a method for controlling illegal use of the conditional access system, capable of minimizing the number of entitlement management messages (EMMs) to be distributed from a head end to a user are provided. Update keys encrypted with user keys and channel management keys encrypted with the update keys are utilized.

Abstract: A system for transmitting and recording digital data is included. Further, a system for transmitting transmit scrambled audio data that is to be recorded on a mini disc reader is included. A system for transmission and recording of digital data includes transmission means adapted to prepare and transmit scrambled digital data together with at least one encrypted control word and a digital recording device adapted to receive and record the scrambled digital data and encrypted control word on a digital support. The digital recording device further includes an access control means adapted to decrypt the control word and thereafter descramble the digital data during playback.