Method of dispatching secret keys to security modules and user cards in a data processing network
First Claim
1. A method for dispatching at least one predetermined secret key, in order to secure the implementation of a provision of service, from a security module (MSC1) of a central processing unit (Cl) of a service implementation network to another security module (MST1) of a terminal (T1) of this network, or to one of the user cards (U1) that can be connected to the terminal (T1) and in turn comprise security modules, characterized in that it comprises transmitting a predetermined implementation key in an encoded form from a security module (MSC1) having a predetermined rank to a security module (MST1 or card U) having a lower rank than the predetermined rank, this encoding comprising using an encoding algorithm contained in the module of predetermined rank and introducing both the predetermined implementation key and at least one diversified key recorded in the module of a rank lower than the predetermined rank, this diversified key necessary for the encoding being obtained by a diversification algorithm contained in the module of predetermined rank and introducing both a basic key of this diversified key and diversification data originating in the module of lower rank, the predetermined encoded implementation key being decoded by the use, in the module of lower rank than the predetermined rank, of a decoding algorithm, which is the inverse of the encoding algorithm.
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Abstract
The present invention relates to a method for dispatching at least one predetermined secret key, in order to make the implementation of a provision of service secure, characterized in that it comprises transmitting a predetermined implementation key in encoded form from a security module (MSCl) having a predetermined rank to a security module (MSTl) or card (U) of a rank lower than the predetermined rank, this encoding comprises using an encoding algorithm and introducing the predetermined implementation key, as well as least one diversified key, this diversified key, necessary for the encoding, being obtained by a diversification algorithm by introducing both a basic key of this diversified key and diversification data originating from the module of lower rank, the predetermined encoded implementation key being decoded by the use, in a module of lower rank than the predetermined rank, of a decoding algorithm which is the inverse of the encoding algorithm.
174 Citations
17 Claims
- 1. A method for dispatching at least one predetermined secret key, in order to secure the implementation of a provision of service, from a security module (MSC1) of a central processing unit (Cl) of a service implementation network to another security module (MST1) of a terminal (T1) of this network, or to one of the user cards (U1) that can be connected to the terminal (T1) and in turn comprise security modules, characterized in that it comprises transmitting a predetermined implementation key in an encoded form from a security module (MSC1) having a predetermined rank to a security module (MST1 or card U) having a lower rank than the predetermined rank, this encoding comprising using an encoding algorithm contained in the module of predetermined rank and introducing both the predetermined implementation key and at least one diversified key recorded in the module of a rank lower than the predetermined rank, this diversified key necessary for the encoding being obtained by a diversification algorithm contained in the module of predetermined rank and introducing both a basic key of this diversified key and diversification data originating in the module of lower rank, the predetermined encoded implementation key being decoded by the use, in the module of lower rank than the predetermined rank, of a decoding algorithm, which is the inverse of the encoding algorithm.
- 16. A network comprising a central unit (C1) and at least one terminal (T1), each including at least one security module (MSC1, MST1), characterized in that prior to the emplacement of the security modules of the network, a predetermined diversified transport key, corresponding to a loading module, is recorded into each security module of the network.
Specification