Abstract: In the present disclosure, a hash function is computed over a known image, for example, an address range in a program. The result of the hash function is known to be the same at two distinct points in time, before the program is run, i.e. signing at build-time, and during the running of the program, i.e. run time. The value that the programmer wishes to hide, i.e. the secret value, is also known at build-time. At build-time, the secret value is combined with the hash in such a way that the combining operation can be reversed at run time. This combined value, i.e. the salt, is stored along with the program. Later, at runtime, the program computes the same hash value as was computed at signing time, and does the reverse combining operation in order to reveal the secret value.

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: A method of protecting the execution of a cryptographic hash function, such as SHA-256, in a computing environment where inputs, outputs and intermediate values can be observed. The method consists of encoding input messages so that hash function inputs are placed in a transformed domain, and then applying a transformed cryptographic hash function to produce an encoded output digest; the transformed cryptographic hash function implements the cryptographic hash function in the transformed domain.

Abstract: A method of obtaining descrambling information at a receiver, the descrambling information for enabling descrambling of scrambled content. A provider verification key is used to access a software image, which has been secured by a provider using a provider signature key corresponding to the provider verification key. A secured version of the descrambling information is received. The accessed software image is used to obtain virtual descrambling information from the secured version of the descrambling information and is provided as inputs to a cryptographic function to produce a given output comprising said descrambling information.

Abstract: There is disclosed a head-end system in which differently processed copies of content portions are reordered such that copies from different content portions are not interleaved in the final transport stream.

Abstract: A fingerprinting method. For each round in a series of rounds: providing to each receiver in a set of receivers a version of a source item of content, the source item of content corresponding to the round. For the round there is a corresponding part of a fingerprint-code for the receiver, the part includes one or more symbols. The version provided to the receiver represents those one or more symbols. One or more corresponding symbols are obtained from a suspect item as a corresponding part of a suspect-code. For each receiver in the set of receivers, a corresponding score that indicates a likelihood that the receiver is a colluding-receiver is updated.

Abstract: The invention relates to a computer-implemented method for providing a data stream comprising a plurality of content elements. At least one of two or more copies of a first content element of the data stream has been watermarked with a different watermark. The method includes watermarking at least one of two or more copies of a second content element with a different watermark. In a rendering order of the data stream, the second content element is at an interval equal to or greater than a watermark interval from the first content element. The watermark interval is set to be sufficiently long so that the output quality of the rendered data stream can either completely recover or at least return to a predetermined acceptable level following the watermarking of the copies of the first content element before watermarking the copies of the next content element.

Abstract: A method for securely obtaining a control word in a chip set of a receiver, said control word for descrambling scrambled content received by the receiver, the method comprising, at the chip set: receiving a secured version of a virtual control word from a conditional access/digital rights management client communicably connected to the chip set; obtaining the virtual control word from the secured version of the virtual control word; and using a first cryptographic function to produce a given output from an input that comprises the virtual control word and either a plurality of signature verification keys or one or more values derived from a plurality of signature verification keys, each signature verification key being associated with a conditional access/digital rights management system, the given output comprising at least one control word, wherein the first cryptographic function has the property that it is infeasible to determine a key pair including a signature key and a signature verification key and an

Abstract: A method of storing an amount of data D in association with a device, the method comprising: obtaining a characteristic C of the device; generating error correction data R for the characteristic C, the error correction data R enabling correction of up to a predetermined number of errors in a version of the characteristic C; combining the characteristic C with the amount of data D and an authentication key K to generate storage data P, wherein said combining is arranged so that the amount of data D and the authentication key K are obtainable using the characteristic C and the storage data P; generating a signature using a signature key, the signature being a digital signature of a quantity of data comprising the storage data P, the amount of data D and the authentication key K, wherein the signature key corresponds to a verification key accessible by the device; generating an authentication code for the error correction data R using the authentication key K, wherein the authenticity of the error correction dat

Abstract: Embodiments of the invention include a conditional access system comprising a terminal and a smartcard, wherein the terminal comprises a user interface for interaction with an end-user, comprising an output for displaying first user interaction data and an input for generating second user interaction data in response to the first user interaction data; and a descrambler configured for descrambling scrambled content, and wherein the smartcard is configured for generating the first user interaction data and allowing, in dependence of the second user interaction data received from the user interface, the descrambler to descramble the scrambled content.

Abstract: A method of controlling distribution of digital content (116) is presented. A version (106) of a program (100) is needed to use the content. A plurality of versions of the program (100) is generated, each version being unique with respect to incorporated code fragments and/or associated locations thereof. The plurality of respective code fragments (118) each cause a processor to perform a respective test regarding a data characteristic on content to be processed by the program for restricting the processing of content for which the permission has not been granted. The respective code fragments (118) are incorporated at respective locations in the program (100) to obtain the version (106) of the program (100).

Abstract: A method and system that provides secure modules that can address Java platform weaknesses and protect Java bytecode during execution time. The secure modules are implemented in C/C++ as an example. Because implementation of the security modules is made in C/C++, this enables use of security technology that secures C/C++ software code.

Abstract: Provided are a system and method for software obfuscation for transforming a program from a first form to more secure form that is resistant to static and dynamic attacks. The method utilizes a sophisticated pre-analysis step to comprehend the function-call structure, the function-call layout, and the entire function call graph of the program, in order to determine strategic points in the program for changing the program. This provides resistance to static attacks by transforming the original function-call layout to a new layout. Changing the layout may include changing the function boundaries. The method also provides resistance to static attacks by transforming the original function-call structure to a new structure to be able to self modify as the transformed program executes in memory. Changing the function-call structure may include modifying when and how functions are called, and/or choosing random paths of execution that lead to the same result.

Abstract: A system and method for transforming a software application comprising binary code and optionally associated data, from an original form to a more secure form. The method includes performing a combination of binary transmutations to the application, and interlocking the transmutations by generating and placing interdependencies between the transmutations, wherein a transmutation is an irreversible change to the application. Different types of the transmutations are applied at varied granularities of the application. The transmutations are applied to the application code and the implanted code as well. The result is a transformed software application which is semantically equivalent to the original software application but is resistant to static and/or dynamic attacks.

Abstract: The invention provides a receiver, a smartcard and a conditional access system for securely obtaining a control word using an entitlement transform tree, wherein intermediate results are cached to improve computational efficiency.

Abstract: The invention enables the shared secret, which is used for encrypting the communication of CWs from a smartcard to a receiver, to cover at least a part of a binary image of firmware that is executing in the receiver. Preferably the shared secret covers the entire binary image of the firmware. Hereto, data from one or more predefined firmware memory locations are read, the set of data forming the shared secret.

Abstract: There is described a method of controlling access to IP streaming content by a plurality of receivers. The method comprises the steps of (a) for each receiver in the plurality of receivers, providing that receiver with access to first control information for that receiver to enable that receiver to access a first portion of the content; (b) identifying a receiver from the plurality of receivers as an identified receiver; (c) updating the first control information so as to provide updated control information for each receiver, the updated control information being associated with a second portion of the content; and (d) configuring each receiver to fetch the updated control information for that receiver. For the identified receiver, the updated control information is invalid such that the identified receiver is unable to fully access the second portion of the content. A server configured to carry out the method is also described.

Abstract: A method of maintaining a list of recommended content items, the method comprising: receiving content list data, the content list data identifying a plurality of content items and comprising relationship data that identifies, for each of one of more of the plurality of content items, an associated set of one or more other content items in the plurality of content items; storing a current list of recommended content items; receiving an identification of a content item in the plurality of content items that has been selected by a user; and forming an updated list of recommended content items based on (a) the current list of recommended content items, (b) the selected content item and (c) the content list data.

Abstract: A method of providing key information from a sender to one or more receivers, the method comprising: obtaining initial key information comprising a plurality of units that assume respective values; forming encoded key information from the initial key information, wherein the encoded key information comprises a plurality of encoded units that correspond to respective units of the initial key information, wherein said forming comprises, for each unit of the initial key information, selecting an encoding from a plurality of invertible encodings associated with said unit and encoding said value assumed by said unit with said selected encoding to form the corresponding encoded unit; and providing the encoded key information to said one or more receivers.

Abstract: A method for generating, from initial content data, output content data for provision to one or more receivers, wherein the initial content data is encoded according to a coding scheme, wherein for a quantity of data encoded according to the coding scheme, the coding scheme provides a mechanism for including in the quantity of encoded data additional data such that a decoder for the coding scheme, upon decoding the quantity of encoded data, does not use the additional data to generate decoded data, the method comprising: selecting one or more portions of the initial content data; for each selected portion, generating a data construct that comprises a plurality of data structures, each data structure comprising data, including a version of the selected portion, that is encrypted using a corresponding encryption process different from each encryption process used to encrypt data in the other data structures, wherein the data construct is arranged such that using a decryption process that corresponds to the encr