| 摘要 |
<p>Method for conveying at least one predetermined secret key with the purpose of rendering secure the operation of a service facility, characterised in that it consists in transmitting a predetermined operating key in encrypted form, from a security module (MSC1) exhibiting a predetermined hierarchical level to a security module (MST1 or card U) of hierarchical level lower than the predetermined level, this enciphering consisting in using an enciphering algorithm and involving the predetermined operating key as well as at least one diversified key, this diversified key required for the enciphering is obtained through a diversifying algorithm involving a base key for this diversified key, as well as diversifying data originating from the module of lower hierarchical level, the predetermined enciphered operating key being deciphered by employing, in the module of hierarchical level lower than the predetermined level, a deciphering algorithm inverse to the enciphering algorithm. …<IMAGE>… </p> |
