Abstract: A method and a cryptographic device for encrypting/decrypting an input message by using an algorithm having as entries, said input message, a cryptographic key, and a complementary unique value used as parameter of the algorithm. The output data is formed by the input message decrypted/encrypted by the algorithm using the cryptographic key and the complementary value. The latter is determined on the basis of a unique value physically bound to an electronic device by using a physically unclonable function (PUF) which is inherent to this device and which is used to generate this unique value from a plurality of physical measurements carried out on components integrated in said device.

Abstract: The present invention provides a solution to the problem of guaranteeing the integrity of software programs by encrypting all or part of each instruction of a program using a key based on all or part of one or a plurality of previous instructions, thus resulting in a different encryption key per instruction. The invention is applicable to software programs whose structures are not necessarily tree-like in nature and is also applicable when the program includes loops, jumps, calls or breaks etc. The invention allows for an exception to be flagged when an encrypted instruction is wrongly decrypted. There is no need for the first instruction to be in clear, since the instruction key may be appropriately initialized as required. The invention can be realized in software or entirely in hardware thereby eliminating the possibility of a third party intercepting a decrypted instruction or a decryption key.

Abstract: The present invention provides a method for decrypting encrypted content transmitted from an operator to a plurality of users where said operator further provides security information allowing for the decryption of said content. The method has the advantage of satisfying the goal of providing the capability for detecting a fraudulent user who retransmits control words extracted from the security information to other users. The method provides for the achievement of the goal without incurring extra overhead in addition to the transmitted content and security information. The method makes use of control words which are based on multiple solutions provided by collisions in mathematical functions and involves the observation of choices of control words retransmitted by the fraudulent user.

Abstract: The present invention provides a method for decrypting encrypted content transmitted from an operator to a plurality of users where said operator further provides security information allowing for the decryption of said content. The method has the advantage of satisfying the goal of providing the capability for detecting a fraudulent user who retransmits control words extracted from the security information to other users. The method provides for the achievement of the goal without incurring extra overhead in addition to the transmitted content and security information. The method makes use of control words which are based on multiple solutions provided by collisions in mathematical functions and involves the observation of choices of control words retransmitted by the fraudulent user.

Abstract: The present invention provides a solution to the problem of guaranteeing the integrity of software programmes by encrypting all or part of each instruction of a programme using a key based on all or part of one or a plurality of previous instructions, thus resulting in a different encryption key per instruction. The invention is applicable to software programmes whose structures are not necessarily tree-like in nature and is also applicable when the programme includes loops, jumps, calls or breaks etc. The invention allows for an exception to be flagged when an encrypted instruction is wrongly decrypted. There is no need for the first instruction to be in clear, since the instruction key may be appropriately initialised as required. The invention can be realised in software or entirely in hardware thereby eliminating the possibility of a third party intercepting a decrypted instruction or a decryption key.

Abstract: Data are converted between an unencrypted and an encrypted format according to the Rijndael algorithm, including a plurality of rounds. Each round is comprised of a fixed set of transformations applied to a two-dimensional array, designating states, of rows and columns of bit words. At least a part of the transformations are applied on a transposed version of the state, wherein rows and columns are transposed for the columns and rows, respectively.

Abstract: A method for implementing one-to-one binary functions defined on the Galois field GF(28) is very useful for forming fast and low power hardware devices regardless of the binary function. The method includes decoding an input byte for generating at least one bit string that contains only one active bit, and logically combining the bits of the bit string according to the binary function for generating a 256-bit string representing a corresponding output byte. The 256-bit string is then encoded in a byte for obtaining the output byte.

Abstract: A method for implementing one-to-one binary functions defined on the Galois field GF(28) is very useful for forming fast and low power hardware devices regardless of the binary function. The method includes decoding an input byte for generating at least one bit string that contains only one active bit, and logically combining the bits of the bit string according to the binary function for generating a 256-bit string representing a corresponding output byte. The 256-bit string is then encoded in a byte for obtaining the output byte.

Abstract: Data are converted between an unencrypted and an encrypted format according to the Rijndael algorithm, including a plurality of rounds. Each round is comprised of fixed set of transformations applied to a two-dimensional array, designated state, of rows and columns of bit words. At least a part of said transformations are applied on a transposed version of the state, wherein rows and columns are transposed for the columns and rows, respectively.

Abstract: Data are converted between an unencrypted and an encrypted format according to the Rijndael algorithm, including a plurality of rounds. Each round is comprised of a fixed set of transformations applied to a two-dimensional array, designating states, of rows and columns of bit words. At least a part of the transformations are applied on a transposed version of the state, wherein rows and columns are transposed for the columns and rows, respectively.