| 摘要 |
<p>A method and a system for subscribing to a symmetric key in an identity scheme, the method comprising the steps of : deriving; by a first entity ('R', 460),a second symmetric key from a first value (recursive value 'N') and a first symmetric key (base symmetic key 'X') which is associated with a second entity; receiving from the first entity the first value and the derived second symmetric ('Y') key by the third entity ('B', 455); receiving the first value by the second entity from the third entity; and deriving by the second entity the second symmetric key from the first value and the first symmetric key. The first entity 'R' is a register (also known as identity provider or trusted entity), the second entity 'A' may be an ID card, the third entity 'B' is the counterparty. In a preferred embodiment, 'R' and 'A' store, or derive, the same base symmetric key.</p> |
