Abstract: A method of scrambling a stream of data includes obtaining from the stream a succession of first sequences of blocks of data. The order of the blocks is reversed in each of the first sequences of blocks to form respective second sequences of blocks of data. The blocks in each second sequence of blocks are encrypted using a cipher in block chaining mode, initialized with a respective initialization vector for each second sequence of blocks. For a succession of first sequences of blocks included in a unit of data within the stream, at least one initialization vector for encrypting a second sequence of blocks formed from a first sequence of blocks in the unit is generated in dependence on at least one block in a preceding first sequence of blocks of the unit.

Abstract: Embodiments include a method and a system for signcrypting data based on elliptic curve cryptography. In a head-end system data is encrypted using a random point R and digitally signed using the random point R. Only the x-coordinate Rx of the random point R and only the signature component ssignature of the signature are added to the data after signcrypting the data. In a smartcard the signcrypted data is verified using the random point R and decrypted using the random point R.

Abstract: A method of providing a stream of data units with scrambling state identifying data and providing a stream of key messages, synchronized with the stream of data units. The scrambling state identifying data includes an identifier value associated with the first decryption key that associates the data units in a third section. Then separating the first and second sections, with scrambling state identifying data lacking an identifier value associated with the decryption key, and providing in a key message coinciding with first or third sections key information. Thereby enabling an authorized decoder to obtain a value of the first decryption key corresponding with the second value of the first encryption key. Encryption of at least part of the clear data units uses the first encryption key is suspended for each data unit in the sequence included in the third section.

Abstract: A method comprising distributing digital data encoding content and arranged into messages from a server to one or more client terminals through a network, each message being decodable by a decoder application on a client terminal, said method including transmitting a plurality of data packets from the server through a network through a network interface of the server, each packet including at least one header and a payload, each payload including at least part of a message, and providing each message to a first of a series of at least one service interface between two layers in a protocol stack, installed on the server, each service interface configured to add at least one packet header to the packet encoding information enabling the client to process the remainder of the packet.

Abstract: In a method of descrambling a scrambled content data object, at least a section of the scrambled content data object is descrambled by applying at least one decryption operation under a key at least partly derivable from a content descrambling key. At least one content descrambling key is obtained from a message received from a conditional access sub-system over a data communication channel. At least one cryptogram of data obtainable from at least one content descrambling key in the message, each of which cryptograms are carried in the message, is decrypted under an associated channel key. A first key is used to establish each channel key. At least the section of the scrambled content data object is descrambled by applying a further decryption operation under a key at least partly derivable from the first key.

Abstract: A method of implementing a state tracking mechanism in a communications session between a server and a client system, wherein, in the course of the communications session, application data is provided to the client system in accessible form only if the client system has a valid value of state tracking information, includes transmitting a message carrying a new value of the state tracking information to the client system. It further includes calculating the value of the state tracking information valid after transmission of the message using as input at least the new value carried in the message and a datum maintained at the client system.

Abstract: A method of authorising conditional access to an encrypted digital data product, includes storing at least one set of entitlements in a secure device, each entitlement including a product identifier and expiry information, receiving entitlement control messages from a decoder system including a device for decrypting encrypted digital data products using control words, each entitlement control message including a product identifier, and in a first mode, returning at least one control word in response to an entitlement control message including a product identifier if the product identifier corresponds to a product identifier in a stored entitlement including expiry information indicating the entitlement to be valid, and, in a second mode, progressively adjusting a counter to a pre-determined value and returning at least one control word in response also to entitlement control messages including a product identifier if the product identifier corresponds to a product identifier in a stored entitlement including

Abstract: A method of partially scrambling a data stream (6) including transport stream packets (7), each transport stream packet (7) having a header (8) and a payload (9), wherein a sequence of transport stream packets (7) has payloads carrying encoded data elements, arranged in units (15), includes: selecting transport stream packets (7) forming a subsequence of the sequence, and scrambling at least part of the payloads (9) of each transport stream packet (7) in the subsequence. The method further includes monitoring the payloads (9) of at least some of the transport stream packets (7) in the sequence for the presence of data (22) indicating a boundary between two subsequent units (15), and, for selected units (15), including at least one of the transport stream packets (7) carrying data forming part of the selected unit (15) in the sub-sequence.

Abstract: The invention provides a method for securing a smart card (100), the smart card comprising processing means (101), a memory (110) for storing in an encrypted fashion a software module (115) to be executed by the processing means, and a decryption means (130) configured for just-in-time decryption of the software module, the method comprising the step of providing the smart card with a white-box implementation of the decryption means. In one embodiment the white-box implementation comprises a white-box implementation of the Lombok cryptographic algorithm.

Abstract: The invention provides a solution for secure and non-manipulatable processing of a data stream in a receiver, possibly in conjunction with a smartcard. A packet identity and a content type identifier associated with the packet identifier are received in encrypted form and securely processed within the receiver to allow an encrypted payload of the data stream to be processed without the possibility to manipulate the content type identifier in an attempt to intercept the payload after decryption.

Abstract: Methods and a systems are described for processing recordable content in a broadcast stream sent to a receiver, wherein said broadcast stream is protected in accordance with a conditional access system and wherein said receiver is configured for storing and consuming content in said broadcast stream in accordance with a digital rights management system. In this methods and systems recording information is sent in one or more entitlement control messages over a broadcast network to a receiver. Using the recording information in the entitlement control messages the receiver is able to store recordable events in a broadcast stream on a storage medium and to consume said recorded events in accordance with a digital rights management system.

Abstract: Methods and a systems are described for processing recordable content in a broadcast stream sent to a receiver, wherein said broadcast stream is protected in accordance with a conditional access system and wherein said receiver is configured for storing and consuming content in said broadcast stream in accordance with a digital rights management system. In this methods and systems recording information is sent in one or more entitlement control messages over a broadcast network to a receiver. Using the recording information in the entitlement control messages the receiver is able to store recordable events in a broadcast stream on a storage medium and to consume said recorded events in accordance with a digital rights management system.

Abstract: The invention provides a method and a system for allowing access to a digital broadcast stream on a client device in a conditional access system, wherein the start time and end time of events in the broadcast stream are predefined. If entitled, a server system transmits for an even the start time and end time to the client device. As long as the current time, which is also transmitted from the server system to the client device, is within the range from the start time to the end time, the client device is allowed to decrypt the broadcast stream. To allow events to extend in time without requiring the generation of a new end time, the start time and end time on the one hand and the current time on the other hand are defined on different timescales.

Abstract: Embodiments of the invention provide a method and a system for fingerprinting a data object at a server system and a method and a system for extracting the fingerprint from the data object at a client system. Sections of a data object are watermarked with known watermark data to create a first and a second variant of the data object, whereby the section boundaries are optionally saved as metadata. Using the metadata, the first and second variant are combined by taking sections from the variants to create a fingerprinted data object. From the fingerprinted data object, the watermark data can be extracted again.

Abstract: A method of external data storage in a system including a primary processing device, having a processor and a primary data storage unit, adapted to run application programs for processing active records in the processor and configured to store data belonging to active records in the primary data storage unit; and a secondary data storage system, accessible to the primary processing device, includes loading data belonging to an active record into the primary data storage unit and externalising the record by transferring at least a piece of data belonging to the record to the secondary data storage system for storage. The step of externalising a record includes the making of a call by an application program using data belonging to the record to an interface, arranged to transfer the piece of data to the secondary data storage system.

Abstract: The invention provides a system and a method for securely providing a secret data from a sender to one or more receivers. The receiver uses a sequence of functions originating from a hierarchy of functions to migrate the secret data from an input transform space to an output transform space using a mathematical transformation under control of one or more seeds. The seeds are provided to the receiver by the sender. The sender conditionally allows the receiver to obtain the secret data by controlling the seeds.

Abstract: Embodiments of the invention provide an improved method and an improved receiver for obtaining a control word. Two or more subkeys are obtained in a receiver. Each subkey was encrypted under control of a key received in an entitlement message or transformed under control of a seed received in an entitlement message. After decryption or transformation, the subkeys are combined to obtain the control word. Typically at least one of the entitlement messages is a positive entitlement message and at least one of the entitlement messages is a negative entitlement message. Embodiments of the invention can be used in a conditional access system such as a Pay-TV system.

Abstract: One embodiment of the present invention sets forth a method for determining a chance that a user is present at a current time while a client device is tuned to a channel by monitoring a user input to the client device and determining a time when the user provides the user input. At the time when the user provides the user input, the chance is assigned an initial value. After that, the chance varies over time according to a first function. The chance that the user is present at the current time is then determined using the initial value and the first function. As a result, a chance of a user being present while a client device plays out media segments may be determined without incurring the costs of providing additional hardware and without requiring the user to register and unregister.

Abstract: Various embodiments of the invention provide a method, a smartcard, a conditional access module (CAM) of a receiver and a receiver, such as e.g. a set-top box, for securely providing a control word from the smartcard to the CAM. In various embodiments, diversification data from the smartcard and the CAM is used to make the encryption key and decryption key to encrypt and decrypt the control word in the smartcard and CAM, respectively, dependent on a user interaction with the receiver, such as e.g. selecting a service in the set-top box.

Abstract: A method for processing packets with encrypted data received by a client from a server through at least one network wherein the data packets comprise at least an encryption header (46) and payload (45), extracting the encryption header (54, 55; 69) from a data packet, extracting and decrypting the encrypted payload to form a clear data, generating a clear data packet segment. Secure packet-based transmission of content data from a server to at least one client comprises retrieving a clear data packet comprising an unencrypted payload, dividing the unencrypted payload into one or more segments, applying an encrypted algorithm to each segment to generate encrypted segments (47), generating encryption header for each encrypted segment composing a packet with encrypted data for each encrypted segment comprising the encrypted header (46), a data packet header and transmission of each of the composed packets to the client.