Nagravision S.a.

Patrick Servet

Didier Hunacek

Marco Macchetti

Olivier Brique

Pierre Sarda

Minh Son Tran

Jean-Bernard Fischer

Jerome Perrine

Jérôme Perrine

A surveillance system connectable to a network, comprising a communication module and a management module; said system being configured to, during an initialization phase: a. intercept a first message being sent to a first device; b. intercept a second message said second message being a response from the first device to the first message; c. calculate a time interval between the interception of the first message and the second message; d. repeat the steps a. to c. to determine further time intervals; e. determine a distribution of said time intervals; f. store the distribution and during a surveillance phase, intercept a third message said message being sent to the first device; intercept a fourth message said fourth message being a response to the third message; calculate a new time interval between the interception of the third and fourth messages; and verify that the new time interval is within the distribution.

Method and system to detect abnormal message transactions on a network

Methods and content consumption devices are disclosed that enable a revocation list to be securely enforced and managed, in terms of enforcing version control and providing granular control of individual capabilities, for example. Aspects also relate to enhanced enforcement control of content consumption control information more generally, for example by enforcing version control of activation messages, and/or granular management of individual capabilities.

Capability revocation in a content consumption device

Method for securing control words within a decoder in charge of descrambling digital content protected by these control words, comprising the following steps: for each descrambling unit of this decoder, loading in a directory a pairing key referenced by an identifier associating said key to a descrambling unit; receiving at least one encrypted control word referenced by an indication allowing to identify the descrambling unit for which it is intended; decrypting the control word by using a first key shared with a security module; identifying in the directory the pairing key whose identifier corresponds to the indication of destination associated to the control word; encrypting this control word by using this pairing key; and storing in a register the control word in a chronological and referenced way.

Method for protecting decryption keys in a decoder and decoder for implementing said method

A system and method to watermark a compressed content encrypted by at least one content key, said content key as well as pre-marking data forming Conditional Access System (CAS) data, said CAS Data being encrypted by a transmission key and comprising at least one signature to authenticate all or part of the CAS Data, said compressed content being received by a client device comprising: a Descrambler having an input to receive the encrypted compressed content and an output to produce an compressed content, a Watermark (WM) inserter directly connected to the output of the Descrambler, said Descrambler and said WM inserter being connected with a Conditioner, said Conditioner executing the following steps: receiving the CAS Data, decrypting the CAS Data with the transmission key, verifying the signature of the CAS Data, and if the signature is valid, transferring the content key to the descrambler and the pre-marking data to the WM inserter, and watermarking by the WM inserter, the decrypted content received by the descrambler using the pre-marking data and the identifier.

Method to watermark a compressed content encrypted by at least one content key

A method for watermarking digital media content received in a form of at least one encrypted sample to which metadata is assigned. Each sample is encrypted by means of a sample key. The metadata comprises first data, second data and a signature resulting from the first and second data. The first data is encrypted by a transport key and comprises at least a content key and watermarking metadata. The second data comprises an initialization vector so that the content key and the initialization vector form a unique pair of cryptographic data equivalent to the sample key. The method comprises the steps of extracting the metadata from the media content, decrypting the first data by using the transport key, authenticating the signed data and, in case of positive outcome, descrambling each sample by using the pair of cryptographic data, and marking each descrambled sample by using the watermarking metadata.

Method for watermarking media content and system for implementing this method

A system and method for securely loading data in a cache memory associated with at least one secure processor that performs data processing by using at least one untrusted external memory storing data to be processed, at least one secure internal cache memory to load or store data, and at least one secure cache translator operating as a memory management unit. The secure cache translator stores, into a secure cache digest table, parameters arranged on persistent and variable data pages. The parameters comprise at least a root digest based on node digests calculated on at least one persistent data page according to a Merkle tree structure. The integrity of the data pages is verified during transfers between the secure internal cache memory and the external memory by comparing a calculated root digest with the root digest stored in the secure cache digest table.

System and method for secure loading data in a cache memory

A method to enforce watermarking instructions by a security module in a receiving device, comprising the steps of receiving a security message by&#x2014;a security module, comprising at least a content key, watermark instructions and security message signature, said watermark instruction activates or deactivates a watermarking module, decrypting&#x2014;a security message with a transmission key, verifying&#x2014;a security message signature, and in case of successful verification, reading a watermarking data from the watermarking module, verifying the authenticity of the watermarking data, and in case of successful verification, transmitting the watermark instructions to the watermark module and the content key to a descrambling module.

Method to enforce watermarking instructions in a receiving device

A method for activating a function of a chipset comprising at least a memory and a calculation module in charge of cryptographic operations, the memory containing at least a seed and the calculation module containing at least one cryptographic algorithm, the method comprising the steps of: receiving at least one of a segmentation key, a global key and a global cryptographic algorithm selector; transmitting at least two items selected from the group consisting of the seed, the received segmentation key, the global key and the global cryptographic algorithm selector, to the calculation module, each of the items being provided by different entities; generating in the calculation module, a temporary key by using one of said at least one cryptographic algorithm of the calculation module and at least the two items; and verifying an authenticity of a received activation message using the temporary key and controlling activation based on the verification.

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Cheseaux-sur-Lausanne, Switzerland

Patrick Servet