Abstract: The invention concerns the securing of the pre-initialization phase of a smart card (CP) with a mutual authentication of this card (CP) storing a symmetric secret key (KM) and an asymmetric public key (n), and a security device (3) storing the same secret key (KM) and the asymmetric secret key (Kpq) corresponding to the public key (n). The card (CP) and the device (3) supply random numbers (NaC). The device (3) is authenticated by transmitting to the card (CP) a cryptogram (SR) derived from the two random numbers using an asymmetric algorithm. The card (CP) is authenticated by calculating a secret session key derived from the random number (NaC), using a symmetric algorithm and the secret key (KM), and by transmitting to the device (3) a cryptogram (CC) derived from the second random number, using the symmetric algorithm and the session key. The dedicated key (KF), encrypted by the session key (KS), is transmitted to the card.

Abstract: The invention concerns a method for secure storage of a piece of so-called sensitive data, for example an encryption key, in a memory (M) of an embedded microchip system, particularly a smart card (CP). The memory (M) comprises two physically distinct storage devices (1, 2), for example a permanent memory of the “ROM” type (1), and a second, re-programmable memory of the “EEPROM” type (2). The piece of sensitive data is divided into at least two parts (d, d′), in a given logical configuration, each of these parts being stored in one of the distinct storage devices (1, 2). An additional piece of verification data, a checksum or hash data, can also be stored in the first storage device (1), at the same time as the first sensitive data part (d).