Abstract: A method of protecting a telecommunication terminal having a chip-card-type personal component which is required for telecommunication network access. The terminal includes a processing unit, at least one operating memory element containing the information necessary to the operation of the terminal, i.e. a terminal operating program, and the data necessary to the program. The method involves: a) encrypting the contents of the operating memory element of the telecommunication terminal using a pre-determined key K which is necessary for decryption; and b) allowing the terminal to commence decryption once the terminal has been started with a start-up program that is saved in a secure memory element and once the key for decryption has been calculated by same.

Abstract: The invention relates to a method of masking a plain datum b having n bits. The inventive method is characterised in that a masked datum m is produced using the following masking function: (I), wherein p is a prime number, bi is the bit at position i of plain datum b, and qi is the prime number at position i in a set of prime numbers (q1, . . . , qn). The invention also relates to a method of masking a biometric print, consisting in: determining a set of s real minutiae which are characteristic of the print; mixing and arranging the real minutiae with t false minutiae; and forming a mixed biometric datum b having n=s+t bits, such that, for any i: bi=1 if position i corresponds to a real minutia, and bi=0 if position i corresponds to a false minutia. The invention can be used to secure a security document such as a bank cheque.

Abstract: A method and associated device for checking a biometric signature by a simple and secure calculation adapted to personal objects of the chip card type. The method is based on the storage within the object of an obscured biometric signature and an associated authentication code. A terminal capturing a fingerprint compares the fingerprint data with the obscured biometric signature transmitted by the card and transfers the result of this comparison to the chip card, which validates this result with the authentication code.

Abstract: A method of protecting a telecommunication terminal having a chip-card-type personal component which is required for telecommunication network access. The terminal includes a processing unit, at least one operating memory element containing the information necessary to the operation of the terminal, i.e. a terminal operating program, and the data necessary to the program. The method involves: a) encrypting the contents of the operating memory element of the telecommunication terminal using a pre-determined key K which is necessary for decryption; and b) allowing the terminal to commence decryption once the terminal has been started with a start-up program that is saved in a secure memory element and once the key for decryption has been calculated by same.

Abstract: The invention relates to a method of masking a plain datum b having n bits. The inventive method is characterised in that a masked datum m is produced using the following masking function: (I), wherein p is a prime number, bi is the bit at position i of plain datum b, and qi is the prime number at position i in a set of prime numbers (q1, . . . , qn) The invention also relates to a method of masking a biometric print, consisting in: determining a set of s real minutiae which are characteristic of the print; mixing and arranging the real minutiae with t false minutiae; and forming a mixed biometric datum b having n=s+1 bits, such that, for any i: bi=1 if position i corresponds to a real minutia, and bi=0 if position i corresponds to a false minutia. The invention can be used to secure a security document such as a bank cheque.

Abstract: A method and associated device for checking a biometric signature by a simple and secure calculation adapted to personal objects of the chip card type. The method is based on the storage within the object of an obscured biometric signature and an associated authentication code. A terminal capturing a fingerprint compares the fingerprint data with the obscured biometric signature transmitted by the card and transfers the result of this comparison to the chip card, which validates this result with the authentication code.