Abstract: A secure method for transmitting a control word between a server and a plurality of processing entities so as to respectively produce and utilize the control word. Preferably such a method is applied to the field of conditional access methods and systems for preventing the fraudulent use of compromised decryption keys resulting from a coalition of pirate hackers.

Abstract: This disclosure relates to methods for generating a prime number, which can be implemented in an electronic device. An example method can include calculating a candidate prime number using a formula Pr=2P·R+1, where P is a prime number and R is an integer. The method can also include applying the Pocklington primality test to the candidate prime number and rejecting the candidate prime number if it fails the Pocklington test. The integer can be generated from an invertible number belonging to a set of invertible elements modulo the product of numbers belonging to a group of small prime numbers greater than 2, where the candidate prime number is not divisible by any number of the group. The prime number P having a number of bits equal to within one bit, to half or a third of the number of bits of the candidate prime number.

Abstract: The invention relates to a method for generating a prime number, implemented in an electronic device, the method including steps of generating a prime number from another prime number using the formula Pr=2P·R+1, where P is a prime number having a number of bits lower than that of the candidate prime number, and R is an integer, and applying the Pocklington primality test to the candidate prime number, the candidate prime number being proven if it passes the Pocklington test. According to the invention, the size in number of bits of the candidate prime number is equal to three times the size of the prime number, to within one unit, the generated candidate prime number being retained as candidate prime number only if the quotient of the integer division of the integer by the prime number is odd.

Abstract: The invention proposes an off-line divisible e-cash scheme where a user can withdraw a divisible coin of monetary value nL (n being for example equal to 2) that he can parceled and spend anonymously and unlinkably. The invention allows to protect the anonymity of honest users and to revoke anonymity only in case of cheat for protocols based on a tree structure without using a trusted third party.

Abstract: The invention relates to a method and a system for conditional access making it possible to prevent the fraudulent use of a subscriber electronic device (1a, 1b, 1m) and to thus effectively combat the fraudulent making available of protected contents. The invention further relates to the adaptation of such a device as well as to a method allowing the revocation of the latter if it is deemed to be illicitly exploited or its possible reinstatement.

Abstract: The invention relates to a method for preventing the fraudulent use of an electronic device and thus for effectively combating the fraudulent dissemination of protected content. The invention further relates to such a device as well as to a method enabling permanent revocation thereof if the device is considered to be unlawfully used or optional reinstatement of the device.

Abstract: The invention concerns the contact-less technology MIFARE, and describes a method to update a state by injecting an IV using a non-linear feedback shift register that makes use of only look-up tables and basic operations on 8-bit words.

Abstract: The invention relates to a method for generating a prime number, implemented in an electronic device, the method including steps of generating a prime number from another prime number using the formula Pr=2P·R+1, where P is a prime number having a number of bits lower than that of the candidate prime number, and R is an integer, and applying the Pocklington primality test to the candidate prime number, the candidate prime number being proven if it passes the Pocklington test. According to the invention, the size in number of bits of the candidate prime number is equal to three times the size of the prime number, to within one unit, the generated candidate prime number being retained as candidate prime number only if the quotient of the integer division of the integer by the prime number is odd.

Abstract: The invention relates to a method for generating a prime number, implemented in an electronic device, the method including steps of calculating a candidate prime number having a number of bits, using the formula: Pr=2P·R+1, where P is a prime number and R is an integer, applying the Pocklington primality test to the candidate prime number, rejecting the candidate prime number if it fails the Pocklington test, generating the integer from an invertible number belonging to a set of invertible elements modulo the product of numbers belonging to a group of small prime numbers greater than 2, so that the candidate prime number is not divisible by any number of the group, the prime number P having a number of bits equal, to within one bit, to half or a third of the number of bits of the candidate prime number.

Abstract: The invention concerns the contact-less technology MIFARE, and describes a method to update a state by injecting an IV using a non-linear feedback shift register that makes use of only look-up tables and basic operations on 8-bit words.

Abstract: The invention relates to a method for generating a session key between two communicating electronic devices not requiring any prerecorded information in one of the two devices and enabling the authentication of one of said devices. The method uses a close collaboration between a symmetrical algorithm and an asymmetrical algorithm.

Abstract: The present invention is a method to ensure a secure exchange of crypted numeric data between two entities, where their decryption depends to the approval of a third entity. The solution uses a combination of Identity Based Encryption scheme, and transcription trap use.

Abstract: The invention relates to a method and a system for conditional access making it possible to prevent the fraudulent use of a subscriber electronic device (1a, 1b, 1m) and to thus effectively combat the fraudulent making available of protected contents. The invention further relates to the adaptation of such a device as well as to a method allowing the revocation of the latter if it is deemed to be illicitly exploited or its possible reinstatement.

Abstract: A secure method for transmitting a control word between a server and a plurality of processing entities so as to respectively produce and utilize the control word. Preferably such a method is applied to the field of conditional access methods and systems for preventing the fraudulent use of compromised decryption keys resulting from a coalition of pirate hackers.

Abstract: The invention relates to a method for preventing the fraudulent use of an electronic device and thus for effectively combating the fraudulent dissemination of protected content. The invention further relates to such a device as well as to a method enabling permanent revocation thereof if the device is considered to be unlawfully used or optional reinstatement of the device.

Abstract: A method for encrypting/decrypting a message includes the initial step of generating keys by the sub-steps of generating a public key; generating a decryption key; and generating a derivation key. For a first entity, the message is encrypted using the public key and a cipher. For a second entity, the cipher is decrypted to find the message. A trapdoor associated with said message is generated. The trapdoor corresponds to a derivative of the derivation key specific to the message. A test cipher is tested, using the trapdoor associated with the message, to determine if the test cipher is an encryption of the message using the public key.

Abstract: The invention relates to a method for generating a session key between two communicating electronic devices not requiring any prerecorded information in one of the two devices and enabling the authentication of one of said devices. The method uses a close collaboration between a symmetrical algorithm and an asymmetrical algorithm.

Abstract: The present invention is a method to ensure a secure exchange of crypted numeric data between two entities, where their decryption depends to the approval of a third entity. The solution uses a combination of Identity Based Encryption scheme, and transcription trap use.

Abstract: A multiply unit includes an extended precision accumulator. Microprocessor instructions are provided for manipulating portions of the extended precision accumulator including an instruction to move the contents of a portion of the extended accumulator to a general-purpose register (“MFLHXU”) and an instruction to move the contents of a general-purpose register to a portion of the extended accumulator (“MTLHX”).

Abstract: Polynomial arithmetic instructions are provided in an instruction set architecture (ISA). A multiply-add-polynomial (MADDP) instruction and a multiply-polynomial (MULTP) instruction are provided.