Abstract: The invention concerns a method for protecting an electronic system implementing a cryptographic calculation process involving a modular exponentiation of a quantity (x), said modular exponentiation using a secret exponent (d), characterized in that said secret exponent is broken down into a plurality of k unpredictable values (d1, d2, . . . , dk), the sum of which is equal to said secret exponent.

Abstract: The invention relates to a method and an architecture for securely accessing virtual objects (Obvi) distributed in systems connected to the internet network (RI), and for obtaining an instance of same. This access is performed via a smart card (2a), through a “web” browser (10). The terminal (1) and the smart card (2a) each comprise a specific protocol layer (13, 23a). The latter comprises intelligent agents (132, 232a1) for establishing two-way data exchange sessions, thereby allowing the smart card (2a) to have a “web” server functionality. The smart card (2a) also comprises intelligent agents, called script translators, and a virtual file management system (8) cooperating with a specialized script-translating intelligent agent (7). Each virtual object (Obvi) is associated with a virtual file of the virtual file management system (8). The specialized intelligent agent (7) presents the browser (10) with a list of the accessible virtual objects (Obvi) and generates methods for accessing these objects.