Patents by Inventor Louis Guillou

Louis Guillou 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).

  • Patent number: 7822986
    Abstract: A method enabling a personal computer to be authenticated by a server is provided. The method comprises the step, which includes for the user in launching the execution of a log-on procedure software, introducing personal identifiers providing access to a signature private key for long-term use relative to the duration of the session. The log-on procedure software produces: identification data of the session Id, a public ephemeral module, a public exponent and at least a pair of ephemeral pubic numbers and ephemeral private numbers related by a generic equation of the type: G=Qv (mod n) or G×Qv=1 (mod n), an ephemeral certificate linking, by means of said signature private key, Id and public ephemeral module. The public ephemeral module is of reduced size relative to the signature private key.
    Type: Grant
    Filed: July 23, 2008
    Date of Patent: October 26, 2010
    Inventor: Louis Guillou
  • Patent number: 7680271
    Abstract: A cryptography method involving a keyholder having a number m?1 of private keys Q1, Q2, . . . , Qm and respective public keys G1, G2, . . . , Gm, each pair of keys (Qi, Gi) (where i=1, . . . , m) satisfying either the relationship G1=Qiv mod n or the relationship Gi×Qiv=1 mod n, where n is a public integer equal to the product of f (where f>1) private prime factors p1, . . . , pf, at least two of which are separate, and the exponent v is a public integer equal to a power of 2. Disclosed is what mathematical structure may be imparted to the public keys for it to be impossible to calculate said private keys from said public parameters in a reasonable time unless said prime factors are known. Devices adapted to implement the method are also disclosed.
    Type: Grant
    Filed: January 24, 2005
    Date of Patent: March 16, 2010
    Inventors: Louis Guillou, Jean-Jacques Quisquater
  • Publication number: 20090063864
    Abstract: A method enabling a personal computer to be authenticated by a server is provided. The method comprises the step, which includes for the user in launching the execution of a log-on procedure software, introducing personal identifiers providing access to a signature private key for long-term use relative to the duration of the session. The log-on procedure software produces: identification data of the session Id, a public ephemeral module, a public exponent and at least a pair of ephemeral pubic numbers and ephemeral private numbers related by a generic equation of the type: G=Qv (mod n) or G×Qv=1 (mod n), an ephemeral certificate linking, by means of said signature private key, Id and public ephemeral module. The public ephemeral module is of reduced size relative to the signature private key.
    Type: Application
    Filed: July 23, 2008
    Publication date: March 5, 2009
    Applicants: France Telecom, Telediffusion de France
    Inventor: Louis Guillou
  • Patent number: 7415614
    Abstract: A method for enabling a personal computer to be authenticated by a server is provided. The method comprises the step, which includes for the user in launching the execution of a log-on procedure software, introducing personal identifiers providing access to a signature private key for long-term use relative to the duration of the session. The log-on procedure software produces: identification data of the session Id, a public ephemeral module, a public exponent and at least a pair of ephemeral pubic numbers and ephemeral private numbers related by a generic equation of the type: Gi?Qiv (mod n) or Gi·Qiv?1 (mod n), an ephemeral certificate linking, by means of said signature private key, Id and public ephemeral module. The public ephemeral module is of reduced size relative to the signature private key.
    Type: Grant
    Filed: March 12, 2002
    Date of Patent: August 19, 2008
    Assignees: France Telecom, Telediffusion de France
    Inventor: Louis Guillou
  • Patent number: 7386122
    Abstract: Proof is established by means of the following parameters: m pairs of private values Q1 and public values G1 m>1, a public module n made of the product of f first factors pj, f>2, a public exponent v, linked to each other by relations of the type: G1.Qiv=1 mod n or G1=Q1v mod n. Said exponent v is such that v=2k where k>1 is a security parameter. Public value G1 is the square g12 of a base number gi that is lower than f first factors pj, so that the two equations: x2=gi mod n and x2=?g1 mod n do not have a solution in x in the ring of the modulo n integers and such that the equation xv=g12 mod n has solutions in x in the ring of the modulus n integers.
    Type: Grant
    Filed: January 27, 2000
    Date of Patent: June 10, 2008
    Assignees: France Telecom, TDF, Math Rizk
    Inventors: Louis Guillou, Jean-Jacques Quisquater
  • Patent number: 7266197
    Abstract: The proof is provided by means of the following parameters: a public module n formed by the product of f prime factors pi, f>2; a public superscript v; m base numbers gi, m>1. The base numbers gi are such that the two equations: x2?gi mod n and x2??gi mod n cannot de solved in x in the ring of integers modulo n, and such that the equation xv?gi2 mod n can be solved in x in the ring of integers modulo n in the case where the public superscript v is in the form v=2k, wherein k is a security parameter.
    Type: Grant
    Filed: January 27, 2000
    Date of Patent: September 4, 2007
    Assignees: France Telcom, TDF, Math Rizk
    Inventors: Louis Guillou, Jean-Jacques Quisquater
  • Publication number: 20070121936
    Abstract: A cryptography method involving a keyholder having a number m?1 of private keys Q1, Q2, . . . , Qm and respective public keys G1, G2, . . . , Gm, each pair of keys (Qi, Gi) (where i=1, . . . , m) satisfying either the relationship Gi=Qiv mod n or the relationship Gi×Qiv=1 mod n, where n is a public integer equal to the product of f (where f>1) private prime factors p1, . . . , pf, at least two of which are separate, and the exponent v is a public integer equal to a power of 2. Disclosed is what mathematical structure may be imparted to the public keys for it to be impossible to calculate said private keys from said public parameters in a reasonable time unless said prime factors are known. Devices adapted to implement the method are also disclosed.
    Type: Application
    Filed: January 24, 2005
    Publication date: May 31, 2007
    Inventors: Louis Guillou, Jean-Jacques Quisquater
  • Patent number: 7080254
    Abstract: The invention concerns a method whereby the proof is established by: m(?1) pairs of private Qi and public Gi=gi2 values; a public module n formed by the product of f(?2) prime factors; an exponent v=2k(k>1), linked by the relationships of the type: Gi?Qiv?1. mod n or Gi?Qiv mod n. Among the m numbers obtained by increasing Qi or its inverse modulo n to modulo n square, k?1 times rank, at least one of them is different from ±gi. Among the 2m equations: x2?gi mod n, x2??gi mod n, at least one of them has solutions in x in the ring of modulo n integers.
    Type: Grant
    Filed: September 29, 2000
    Date of Patent: July 18, 2006
    Assignee: France Telecom
    Inventors: Louis Guillou, Jean-Jacques Quisquater
  • Publication number: 20040133781
    Abstract: The invention concerns a method enabling a personal computer (1) to be authenticated by a server (2). The method comprises the step, which consists for the user in launching the execution of a log-on procedure software, by introducing personal identifiers (21) providing access to a signature private key (14) for long-term use relative to the duration of the session. The log-on procedure software produces: identification data of the session Id, a public ephemeral module n (9), a public exponent v and at least a pair of ephemeral pubic numbers G (11) and ephemeral private numbers Q (12) related by a generic equation of the type: G=Qv (mod n) or G×Qv=1 (mod n), an ephemeral certificate (13) linking, by means of said signature private key (14), Id (8) and n (9). The public ephemeral module n (9) is of reduced size relative to the signature private key (14).
    Type: Application
    Filed: March 8, 2004
    Publication date: July 8, 2004
    Inventor: Louis Guillou
  • Patent number: 5742681
    Abstract: Process for the broadcasting of programmes with progressive conditional access and separation of the information flow, as well as the corresponding receiver,In order to form the elementary flow, groups of m successive elements of the multiplex are taken and for forming the complimentary flow groups of p successive elements of the multiplex are taken.Application to television with entitlement checking.
    Type: Grant
    Filed: April 4, 1995
    Date of Patent: April 21, 1998
    Assignees: France Telecom, Telediffusion de France
    Inventors: Jean-Luc Giachetti, Louis Guillou, Jean-Claude Pacaud
  • Patent number: 5442701
    Abstract: A process for broadcasting conditional access programs which permits a progressive access. Scrambled program data is transmitted along with partial access checking messages and complete access checking messages such that subscribers having a partial access right may descramble portions of the scrambled data corresponding to information regarding only the identity of the conditional access programs, and subscribers having a complete access right may descramble the remainder of the scrambled data and view the conditional access programs. The conditional access programs may be television pictures, radio programs, or data broadcasts.
    Type: Grant
    Filed: December 27, 1993
    Date of Patent: August 15, 1995
    Assignees: France Telecom Establissement Autonome de Droit Public, Telediffusion de France S.A.
    Inventors: Louis Guillou, Jean-Luc Giachetti, Alain Gelly
  • Patent number: 5218637
    Abstract: According to the invention, the chip card issues a first certificate comprising its letter of credentials (Crc), an exponential (X), an optional message (M), these quantities being signed. The security module verifies the signature and in return issues a second certificate containing its letter of credentials (Crm), an exponential (Y), an optional message (M'), a cryptogram (C), these quantities being signed. A common secret key is constituted between the card and the security module by the exponentials and allows the card to interpret the cryptogram addressed to it and to act in accordance therewith.
    Type: Grant
    Filed: June 11, 1991
    Date of Patent: June 8, 1993
    Assignee: L'Etat Francais represente par le Ministre des Postes, des Telecommunications et de l'Espace
    Inventors: Didier Angebaud, Jean-Luc Giachetti, Louis Guillou, Jean-Jacques Quisquater
  • Patent number: 4947428
    Abstract: According to the invention, the control messages are constituted by a general addressing message (GCM), followed by shared addressing messages (SACM). The message (GCM) contains all the information common to all the user groups and a confirmation data item of the group of users and the messages (SACM) a shared address. Thus, the group is defined in a manner inherent in the control messages and can undergo reconfiguration at any time.Application to more particularly satellite broadcasting of television programmes.
    Type: Grant
    Filed: May 12, 1989
    Date of Patent: August 7, 1990
    Assignees: Etat Francais, represente par le Ministere des Postes, des Telecommunications et de l'Espace (C.N.E.T.), Telediffusion de France S.A.
    Inventors: Louis Guillou, Joseph Blineau, Francoise Coutrot, Vincent Lenoir
  • Patent number: 4807288
    Abstract: One chip microprocessor, which is more particularly designed to execute culation algorithms of a public code encoding system formed by a public function and a secret inverse function of the type comprising at least one programmable read-only memory, a processing unit and an input/output device, wherein it comprises a memory, in which is recorded at least one algorithm corresponding to the performance of said secret function, and wherein the programmable read-only memory contains the secret parameters constituting the secret code and recorded in an area of the read-only memory which is inaccesible from the outside, the processing unit including the multiplying circuits necessary for the execution of the algorithm.
    Type: Grant
    Filed: November 30, 1983
    Date of Patent: February 21, 1989
    Assignees: C.I.I. Honeywell Bull, Etat Francais represente par le Ministre des P.T.T. (C.N.E.T.), Establissement Public de diffusion dit Telediffusion de France
    Inventors: Michel Ugon, Louis Guillou
  • Patent number: 4797919
    Abstract: A receiver having an interface arrangement for connection between a television circuit and a conditional access sub-system conveys data via a bus having a four frame bus cycle period with a bit rate corresponding to the line rate. During a first part of the bus cycle period data is conveyed from the receiver to the sub-system sequentially as follows:i. an address block of 1 byte with the unique address of the sub-system with which the receiver is in communication,ii. a status block of 1 byte providing status information for the following blocks in the first part,iii,iv,v. three data blocks each of 93 bytes and each containing an entitlement message,vi. a keying block of 1 byte conveying keyboard or remote control commands, andvii,viii. a further block of either 1/2 byte (vii) or 21/2 bytes (vii+viii) conveying frame count information.
    Type: Grant
    Filed: November 25, 1986
    Date of Patent: January 10, 1989
    Assignees: U.S. Philips Corporation, Etablissement Public de Diffusion de France, Etat Francais
    Inventors: Bruce Murray, Louis Guillou, Francoise M. R. Coutrot