PROCÉDÉS ET DISPOSITIFS POUR SYSTÈMES DE CRYPTAGE SÉCURISÉS FONDÉS SUR L'IDENTITÉ COMPORTANT DEUX CENTRES DE CONFIANCE

摘要

A transmitter device (103) for sending an encrypted message to a receiver device (105) in an identity-based cryptosystem (100), the identity-based cryptosystem (100) comprising a transmitter trusted center (101) connected to the transmitter device (103) and a receiver trusted center (102) connected to the receiver device (105). The transmitter device (103) is configured to:- receive, from the transmitter trusted center (101), two public authentication keys;- check if a set of conditions related to a transmitter trusted center public key, to a receiver trusted center public key, and to a transmitter authentication key comprised in the two public authentication keys are satisfied;- determine a ciphertext set comprising an encrypted message if the set of conditions are satisfied;- send the ciphertext set to the receiver device (105).