| Patent application number | Description | Published |
|---|
| 20090232303 | Copy Protection Method for Digital Data Stored on a Medium - A method of protection against the copying of digital data stored on an information carrier envisages, on the basis of a first identification of an encryption of the digital data and of a second identification of a watermarking of digital data, the determination of a first mark if it has been possible to identify the encryption and the watermarking. A third identification of a type of the information carrier is followed by the determination of a second mark if it has been possible to determine the first mark and if has been possible to identify a determined type of information carrier. A fourth identification of cryptographic signature data accompanying the digital data is followed by the determination of a third mark if it has been possible to determine the second mark and if it has been possible to identify a cryptographic signature datum. A permission for digital copying of the digital data is delivered if it has been possible to determine the third mark | 09-17-2009 |
| 20100284530 | Method for decoding a probabilistic anti-collusion code - The invention relates to a method for decoding a probabilistic anti-collusion code intended to identify at least one sequence of code present in a multimedia content having been used to create an illegal copy of this multimedia content, this method comprising a step of estimating the collusion strategy used to constitute the illegal copy associated with a step of identifying the sequences having been used in creating the illegal copy. The estimation of the collusion strategy used and the identification of sequences having been used to create the illegal copy are carried out sequentially and iteratively in order to refine the precision of each of these according to the following steps: Creating two parameters, a vector of probabilities of the presence of a sequence in the collusion and a vector of probabilities θ representing the collusion strategy; Initialising the iterative method by initialising one of the two parameters; Estimating the parameter vector of probabilities of the presence of a sequence in the collusion; Estimating the parameter vector of probabilities θ of the collusion strategy which maximises the probability of the collusion strategy; Iterating the steps c) and d) until a determined number of iterations or until convergence of the parameter vector of probabilities θ of the collusion strategy; Identifying at least one sequence of the code present in a multimedia content having been used to create the illegal copy. | 11-11-2010 |
| 20100287614 | Decoding method for a probabilistic anti-collusion code comprising the selection of the collusion strategy - The invention relates to a decoding method for a probabilistic anti-collusion code aiming to identify at least one sequence of the code present in a multimedia content having served in the creation of an illegal copy of the multimedia content, this method comprising a step of selection of the collusion strategy used to constitute the illegal copy from among a set of collusion strategy models. In addition, the invention relates to a method for filtering sequences of a probabilistic anti-collusion code for the decoding of this code aiming to identify at least one sequence of the code present in a multimedia content having served in the creation of an illegal copy of the multimedia content comprising a step of selection of a sub-group of the smallest possible sequences of code containing at least one sequence present in a multimedia content having served in the creation of the illegal copy by comparing for each sequence of the code and for a selected given symbol index, the symbol of the sequence of the code with the symbol of the sequence contained in the illegal copy. | 11-11-2010 |
