公开(公告)号：FR2851668A1

公开(公告)日：2004-08-27

申请号：FR0302230

申请日：2003-02-24

Applicant: ST MICROELECTRONICS SA

Inventor： ZAHRA CLAUDE ,  TEGLIA YANNICK

IPC: G01R31/317 ,  G06F21/74 ,  G06K19/07 ,  G06F11/26 ,  G06K19/073

Abstract: The device has a ROM (10) storing a preset value composed of data words. A non-volatile programmable memory (12) is controlled for storing the preset value. A comparator (16) indicates how many data words of the value stored in memory (12) are similar to the words stored in ROM. A control unit (18) inactivates an operation mode selection signal when the number of similar words is greater than a preset threshold. Independent claims are also included for the following: (a) an integrated circuit (b) a selection process for operation mode of an integrated circuit between a stand by mode and a slave mode.

公开(公告)号：FR2820576B1

公开(公告)日：2003-06-20

申请号：FR0101685

申请日：2001-02-08

Applicant: ST MICROELECTRONICS SA

Inventor： ROMAIN FABRICE ,  TEGLIA YANNICK

IPC: G09C1/00 ,  H04L9/06

Abstract: The protected method of cryptographic computation includes N computation rounds successively performed to produce an output data from an input data and a private key. The method also includes a first masking stage to mask the input data, so that each intermediate data used or produced by a computation round is masked, and a second masking stage to mask data manipulated inside each computation round.

公开(公告)号：FR2820577B1

公开(公告)日：2003-06-13

申请号：FR0101684

申请日：2001-02-08

Applicant: ST MICROELECTRONICS SA

Inventor： ROMAIN FABRICE ,  TEGLIA YANNICK

IPC: G09C1/00 ,  H04L9/06 ,  H04L9/08

Abstract: A secured method of cryptographic computation to generate output data from input data and from a secret key includes a derived key scheduling step to provide a derived key from the secret key according to a known key scheduling operation. The method also includes a masking step, performed before the derived key scheduling step, to mask the secret key so that the derived scheduled key is different at each implementation of the method. The present method and component can be used in transfer type applications, such as bank type applications.

公开(公告)号：FR2820577A1

公开(公告)日：2002-08-09

申请号：FR0101684

申请日：2001-02-08

Applicant: ST MICROELECTRONICS SA

Inventor： ROMAIN FABRICE ,  TEGLIA YANNICK

IPC: G09C1/00 ,  H04L9/06 ,  H04L9/08

Abstract: 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.

公开(公告)号：FR2820576A1

公开(公告)日：2002-08-09

申请号：FR0101685

申请日：2001-02-08

Applicant: ST MICROELECTRONICS SA

Inventor： ROMAIN FABRICE ,  TEGLIA YANNICK

IPC: G09C1/00 ,  H04L9/06

Abstract: The invention concerns a secure cryptographic method comprising N cycles of calculation successively carried out to obtain an output from an input and a secret key. The invention is characterised in that it consists in: producing a first masking level to mask the input so that each data used or produced by a cycle of calculation should be masked, and producing a second masking level to mask data manipulated within each cycle of calculation. The invention also concerns an electronic component using such a method. The invention is particularly interesting for banking transactions or more generally secure transfer operations.