Abstract: A method for backing a user secret and recovering a user secret. A set of mandatory trustees possessing a public key and a set of non-mandatory trustees possessing a public key are determined. A predetermined limit value of a number of partitions necessary for recovering the secret is selected by the user. A number of primary partitions equal to the number of mandatory trustees is generated in response to the determination that the set of non-mandatory trustees is empty. A number of primary partitions equal to the number of mandatory trustees plus one is generated in response to the determination that the set of non-mandatory trustees is not empty. Each partition is encrypted using the public key of the corresponding trustee and each encrypted partition is stored in a server.

Abstract: A security method in a terminal comprising a chip card offering secure functions, a user interface, a module for interfacing with the chip card and suitable for shutting down or introducing the electrical supply to the chip card. After shutdown of the chip card with the terming being kept on, the interface module introduces the electrical supply to the chip card, encrypts a command for resumption of utilization of the secure functions with a negotiated key stored by the interfacing module, and dispatches the encrypted command to the chip card. The interface module utilizes the secure functions of the chip card when the resumption command decrypted by the chip card is recognized as a resumption command by the chip card.

Abstract: A security method in a terminal comprising a chip card offering secure functions, a user interface, a module for interfacing with the chip card and suitable for shutting down or introducing the electrical supply to the chip card. After shutdown of the chip card with the terming being kept on, the interface module introduces the electrical supply to the chip card, encrypts a command for resumption of utilization of the secure functions with a negotiated key stored by the interfacing module, and dispatches the encrypted command to the chip card. The interface module utilizes the secure functions of the chip card when the resumption command decrypted by the chip card is recognized as a resumption command by the chip card.