Patents by Inventor Christophe Giraud

Christophe Giraud has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20140075203
    Abstract: A method of testing security of an electronic device against a combination of a side-channel attack and a fault-injection attack implemented during a method of cryptographic processing that includes: delivering a message signature based on a secret parameter and implementing a recombination of at least two intermediate values according to the Chinese remainder theorem; and verifying the signature on the basis of at least one public exponent. The method of testing includes: transmitting a plurality of messages to be signed by said electronic device; disturbing each message, including modifying the message by inserting an identical error for each message, before executing a step of determining one of the intermediate values; and analyzing physical measurements, obtained during the step of verifying the signature as a function of the message to be signed, the identical error for each message, and an assumption of a value of part of the secret parameter.
    Type: Application
    Filed: September 9, 2013
    Publication date: March 13, 2014
    Applicant: OBERTHUR TECHNOLOGIES
    Inventors: Guillaume Barbu, Alberto Batistello, Christophe Giraud, Soline Renner
  • Publication number: 20140025940
    Abstract: A secure element includes a boot program comprises instructions for the execution a startup step to determine if a non-volatile memory stores an active operating system, and, in the affirmative, to launch execution of the operating system, an authentication step of a updater device, as a function of first authentication data determined by a secure element and second authentication data received from the updater device, and, in response to the authentication step, a storage step of a new operating system received from the update, device in the non-volatile memory and an activation step of the new operating system, when said instructions are executed by a microprocessor.
    Type: Application
    Filed: July 19, 2013
    Publication date: January 23, 2014
    Applicant: OBERTHUR TECHNOLOGIES
    Inventors: Christophe Giraud, Olivier Chamley, Gregoire Godel
  • Patent number: 8453261
    Abstract: This microcircuit card includes means for detecting an attack on the card, command means (130) capable of charging a charge pump (120) capable of applying a programming voltage (UP) to command a write operation into a cell (110) of a nonvolatile memory when an attack is detected, and a capacitor (140) arranged so as to be supplied with power during normal operation and to supply said charge pump (120) with power only when an attack is detected. The card (100) being characterized in that said capacitor (140) also supplies power to the command means (130) when an attack is detected.
    Type: Grant
    Filed: December 13, 2011
    Date of Patent: May 28, 2013
    Assignee: Oberthur Technologies
    Inventors: Nicolas Morin, Christophe Giraud
  • Publication number: 20130117844
    Abstract: A microcircuit card (200) includes means for detecting an attack on the card, and command means (130) capable of blowing a fuse (250) of the card when an attack is detected.
    Type: Application
    Filed: December 13, 2011
    Publication date: May 9, 2013
    Applicant: OBERTHUR TECHNOLOGIES
    Inventors: Nicolas Morin, Christophe Giraud
  • Patent number: 8386791
    Abstract: The invention relates to a secure data processing method comprising the steps of generating (E204; E304) a first random value (A1); executing (E206; E306) a first cryptographic algorithm (FK) using the first random value (A1); generating (E208; E308) a second random value (A2); executing (E210; E310) a second cryptographic algorithm (FK; GK) using the second random value (A2); and generating a result (V) to verify that the first algorithm (FK) was properly executed.
    Type: Grant
    Filed: March 7, 2005
    Date of Patent: February 26, 2013
    Assignee: Oberthur Technologies
    Inventors: Régis Bevan, Christophe Giraud, Hugues Thiebeauld De La Crouee
  • Patent number: 8311212
    Abstract: A data processing method comprises the following steps: determining a first result data word from a first input data word and a first secret data word; obtaining a first compressed data word from the first result data word or the first input data word using a compression algorithm; determining a second result data word from a second input data word and a second secret data word; obtaining a second compressed data word from the second result data word using the compression algorithm; comparing the first compressed data word and the second compressed data word.
    Type: Grant
    Filed: August 1, 2008
    Date of Patent: November 13, 2012
    Assignee: Oberthur Technologies
    Inventors: Christophe Giraud, Hugues Thiebeauld de la Crouee
  • Patent number: 8266423
    Abstract: A method for securing a program against attacks by error, i.e. in a chip card, wherein at least one jump instruction, including a relative address chosen from a plurality of possible relative addresses, is identified in the program, wherein the at least one jump instruction makes it possible to reach a targeted address inside the memory area extending before and after the jump instruction and regrouping the plurality of possible relative addresses, inside the memory area, wherein an instruction to be preserved is identified and, in order to secure at least the instruction, at least one first non-operative batch including at least one instruction is inserted, the insertion being carried out in such a way as to ensure that the insertion is compatible with maintenance of the address targeted by the jump instruction inside the memory area and that the insertion is compatible with the normal running of the program.
    Type: Grant
    Filed: October 18, 2005
    Date of Patent: September 11, 2012
    Assignee: Oberthur Technologies
    Inventors: Christophe Giraud, Hugues Thiebeauld De La Crouee
  • Publication number: 20120151608
    Abstract: This microcircuit card includes means for detecting an attack on the card, command means (130) capable of charging a charge pump (120) capable of applying a programming voltage (UP) to command a write operation into a cell (110) of a nonvolatile memory when an attack is detected, and a capacitor (140) arranged so as to be supplied with power during normal operation and to supply said charge pump (120) with power only when an attack is detected. The card (100) being characterized in that said capacitor (140) also supplies power to the command means (130) when an attack is detected.
    Type: Application
    Filed: December 13, 2011
    Publication date: June 14, 2012
    Applicant: OBERTHUR TECHNOLOGIES
    Inventors: Nicolas MORIN, Christophe Giraud
  • Patent number: 8180046
    Abstract: A method for protecting an electronic entity with encrypted access, against DFA (Differential Fault Analysis) attacks which includes: storing the result of a selected step (Rm, Kn) of an iterative process forming part of the cryptographic algorithm and in performing once more at least part of the steps of the iterative process up to a new computation of a result corresponding to the one which has been stored, comparing the two results and denying distribution of an encrypted message (MC) if they are different.
    Type: Grant
    Filed: August 9, 2010
    Date of Patent: May 15, 2012
    Assignee: Oberthur Technologies
    Inventor: Christophe Giraud
  • Publication number: 20110029784
    Abstract: A method of cryptographic processing of data (X), in particular a method protected against fault injection attacks, and an associated device. The processing includes at least one transformation (100, 1001-1006) of an input data item (s) into a result data item (s?). In this case the method includes a step (E204) of verifying the transformation including the following steps: obtaining (E206) a first data item (DV(s?)) that is compressed by applying a compression operation (110, MDV, ADV) to the result data item (s?); obtaining (E208) a second compressed data item (DV(s)) that is compressed by applying the compression operation (110, MDV, ADV) to the input data item (s); determining (E210) a verification data item (DV(s)?) by applying the transformation (100, 1001-1006) to the second compressed data item (DV(s)) and; comparing (E212) the verification data item and the first compressed data item.
    Type: Application
    Filed: July 30, 2010
    Publication date: February 3, 2011
    Applicant: OBERTHUR TECHNOLOGIES
    Inventors: Laurie GENELLE, Christophe GIRAUD, Emmanuel PROUFF
  • Publication number: 20100322421
    Abstract: A method for protecting an electronic entity with encrypted access, against DFA (Differential Fault Analysis) attacks which includes: storing the result of a selected step (Rm, Kn) of an iterative process forming part of the cryptographic algorithm and in performing once more at least part of the steps of the iterative process up to a new computation of a result corresponding to the one which has been stored, comparing the two results and denying distribution of an encrypted message (MC) if they are different.
    Type: Application
    Filed: August 9, 2010
    Publication date: December 23, 2010
    Applicants: OBERTHUR TECHNOLOGIES
    Inventor: Christophe GIRAUD
  • Publication number: 20100241863
    Abstract: The invention concerns a method for reproducing digital content including the following steps: receiving (E222) an identifier (Id?) of the digital content from a secure electronic entity; extracting (E226) a digital watermark of the digital content; controlling (E232) the reproduction of the content based on a comparison between the extracted watermark and the identifier. The invention concerns a reproducing device, an electronic entity and related systems.
    Type: Application
    Filed: March 27, 2007
    Publication date: September 23, 2010
    Applicant: FRANCE TELECOM
    Inventors: Christophe Giraud, Jean-Bernard Fischer, Caroline Fontaine, Abdellatif Benjelloun-Touimi, Michel Milhau, Benoît Prady
  • Patent number: 7796750
    Abstract: A method for protecting an electronic entity with encrypted access, against DFA (Differential Fault Analysis) attacks which includes: storing the result of a selected step (Rm, Kn) of an iterative process forming part of the cryptographic algorithm and in performing once more at least part of the steps of the iterative process up to a new computation of a result corresponding to the one which has been stored, comparing the two results and denying distribution of an encrypted message (MC) if they are different.
    Type: Grant
    Filed: April 2, 2003
    Date of Patent: September 14, 2010
    Assignee: Oberthur Technologies
    Inventor: Christophe Giraud
  • Publication number: 20090254761
    Abstract: A secure data processing method includes the following steps: padding (E206) a memory area (MAC?) with a pad value (A); writing (E208) a first datum in the memory area (MAC?); in the area, reading (E210) a second datum with at least one part of the first datum as it was written in the memory area (MAC?); and executing an operation (E210) using the second datum.
    Type: Application
    Filed: April 14, 2005
    Publication date: October 8, 2009
    Inventors: Hugues Thiebeauld De La Crouee, Christophe Giraud
  • Publication number: 20090240756
    Abstract: A data processing method, whereby an element is subjected to a first operation with a given operand. The method includes a step of updating by a second operation a first variable (B; a0; S?p, S?q) or a second variable (A; a1; Sp, Sq), depending on whether a corresponding bit of the operand=0 or 1; and a step of testing a relationship between a first value (B; a0; S?) derived from the first variable and a second value (A; a1; S) derived from the second variable. A related device is also disclosed.
    Type: Application
    Filed: March 27, 2006
    Publication date: September 24, 2009
    Applicant: OBERTHUR CARD SYSTEMS SA
    Inventors: Arnaud Boscher, Christophe Giraud, Robert Naciri
  • Publication number: 20090170477
    Abstract: A method to mask static cell identifiers or static location area codes of a mobile network a mobile terminal and a masking module integrated in equipment belonging to the architecture of the network under consideration, of generating all or part of dynamic cell identifiers or dynamic location area codes from static identifiers or codes so as to make their geographical conversion impossible for an outside service other than services authenticated by the operator. The disclosed embodiments propose a masking device to mask static identifiers or codes including either a module masking static identifiers or codes, integrated in a BSC for GPS or GPRS or in a RNC for UMTS, or another masking module masking all or part of the static identifiers or codes integrated in network equipment close to the operator's platform.
    Type: Application
    Filed: December 3, 2008
    Publication date: July 2, 2009
    Applicant: SOCIETE FRANCAISE DE RADIOTELEPHONE
    Inventors: Michael Bensimon, Eric Lebomin, Christophe Giraud-Sauveur, Nicolas Prunel
  • Publication number: 20090034717
    Abstract: A data processing method comprises the following steps: determining a first result data word from a first input data word and a first secret data word; obtaining a first compressed data word from the first result data word or the first input data word using a compression algorithm; determining a second result data word from a second input data word and a second secret data word; obtaining a second compressed data word from the second result data word using the compression algorithm; comparing the first compressed data word and the second compressed data word.
    Type: Application
    Filed: August 1, 2008
    Publication date: February 5, 2009
    Applicant: OBERTHUR TECHNOLOGIES
    Inventors: Christophe GIRAUD, Hugues Thiebeauld De La Crouee
  • Patent number: 7394901
    Abstract: An exchange of information between a communication entity e.g. a mobile telephone and the operator server upon which it is dependent, in order to carry out authentication operations by exchanging keys and using cryptography algorithms. According to the invention, an algorithm is used, comprising: algorithmic treatments using, as input data, all or part of a random number and operating keys derived from two keys, and a combined treatment using data derived from algorithmic treatments in order to provide results to enable the linkage.
    Type: Grant
    Filed: March 12, 2003
    Date of Patent: July 1, 2008
    Assignee: Oberthur Technologies
    Inventors: Jean-Bernard Fischer, Christophe Giraud
  • Publication number: 20080040812
    Abstract: Method for security loading of at least one residual memory space including at least one program, in particular in a smart card, consists in carrying out successive cycles for selecting (E13, E23, E33) at least one type of data from a predetermined authorized data set, wherein said authorized data set excludes at least one type of data corresponding to a determined instruction, and in introducing (E14, E24, E34) the at least one type of data selected from the at least one residual memory space in such a way that at least one part of the residual memory space is loaded.
    Type: Application
    Filed: December 19, 2005
    Publication date: February 14, 2008
    Applicant: OBERTHUR CARD SYSTEMS SA
    Inventors: Christophe Giraud, Antoine Lemarechal
  • Publication number: 20070250703
    Abstract: A method for securing a program against attacks by error, i.e. in a chip card, wherein at least one jump instruction, including a relative address chosen from a plurality of possible relative addresses, is identified in the program, wherein the at least one jump instruction makes it possible to reach a targeted address inside the memory area extending before and after the jump instruction and regrouping the plurality of possible relative addresses, inside the memory area, wherein an instruction to be preserved is identified and, in order to secure at least the instruction, at least one first non-operative batch including at least one instruction is inserted, the insertion being carried out in such a way as to ensure that the insertion is compatible with maintenance of the address targeted by the jump instruction inside the memory area and that the insertion is compatible with the normal running of the program.
    Type: Application
    Filed: October 18, 2005
    Publication date: October 25, 2007
    Applicant: Oberthur Card System SA
    Inventors: Christophe Giraud, Hugues Thiebeauld De La Crouee