| 摘要 |
<p>The invention concerns a secure method for cryptographic calculation to supply an output (MS) from an input (ME) and a secret key (K0), the method comprising several key calculating steps (ET2), each supplying an updated derivative key (M'1, M'2) from a derivative key previously calculated in accordance with a known key calculating law, the first updated derivative key (M'1) being obtained from the secret key (K0). The invention is characterised in that the method further comprises a masking step (ET1) carried out prior to a first key calculating step (ET2), to mask the secret key (K0) so that the updated derivative key (M'1, M'i) is different at each implementation of the method. The invention is applicable to banking transactions, or more generally secure transfer operations.</p> |
