Other

France Telecom

Etablissement Public De Diffusion Dit 'telediffusion De France'

U.S. Philips Corporation

L'etat Francais, Represente Par Le Secretaire D'etat Aux Poste Et

Telediffusion De France

Telediffusion De France S.a.

Etat Francais

Cii Honeywell Bull

France Telecom Establissement Autonome De Droit Public

L'etat Francais Represente Par Le Ministre Des Postes, Des

Etat Francais Represente Par Le Ministere Des Postes, Des

Establissement Public De Diffusion Dit 'telediffusion De France'

France Telcom

Louis C Guillou

Jean-Jacques Quisquater

Jean-Luc Giachetti

Michel Ugon

Arthur G Mason

Jean-Marie C Nicolas

Bruce Murray

Gerald O Crowther

Peter R Brennand

Joseph Blineau

Claude Sechet

Didier Angebaud

Alain Gelly

Wilhelmus M Dorn

Francoise Coutrot

Ambroise Le Rest

Raymond Le Bris

Henry J Beker

Stanley M Edwardson

Vincent Lenoir

Peter M Jenner

Luc Emiel Boes

Edmund R Brown

Jean-Claude Pacaud

Stephen R Ely

Sylvia M Jennings

Michael J Knee

Francoise M Coutrot

Gerard Babonneau

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=Q(mod n) or G&#xd7;Q=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.

Cryptographic authentication with ephemeral modules

A cryptography method involving a keyholder having a number m&#x2267;1 of private keys Q, Q, . . . , Qand respective public keys G, G, . . . , G, each pair of keys (Q, G) (where i=1, . . . , m) satisfying either the relationship G=Qmod n or the relationship G&#xd7;Q=1 mod n, where n is a public integer equal to the product of f (where f&#x3e;1) private prime factors p, . . . , p, 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.

Zero-knowledge proof cryptography methods and devices

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: G&#x2261;Q(mod n) or G&#xb7;Q&#x2261;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.

Proof is established by means of the following parameters: m pairs of private values Qand public values Gm&#x3e;1, a public module n made of the product of f first factors p, f&#x3e;2, a public exponent v, linked to each other by relations of the type: G.Q=1 mod n or G=Qmod n. Said exponent v is such that v=2where k&#x3e;1 is a security parameter. Public value Gis the square gof a base number gthat is lower than f first factors p, so that the two equations: x2=gmod n and x=&#x2212;gmod n do not have a solution in x in the ring of the modulo n integers and such that the equation x=gmod n has solutions in x in the ring of the modulus n integers.

Method for proving the authenticity or integrity of a message by means of a public exponent equal to the power of two

The proof is provided by means of the following parameters: a public module n formed by the product of f prime factors p, f&#x3e;2; a public superscript v; m base numbers g, m&#x3e;1. The base numbers gare such that the two equations: x&#x2261;gmod n and x&#x2261;&#x2212;gmod n cannot de solved in x in the ring of integers modulo n, and such that the equation x&#x2261;gmod 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=2, wherein k is a security parameter.

Method, system, device for proving the authenticity of an entity and/or the integrity and/or the authenticity of a message using specific prime factors

The invention concerns a method whereby the proof is established by: m(&#x2267;1) pairs of private Qand public G=gvalues; a public module n formed by the product of f(&#x2267;2) prime factors; an exponent v=2(k&#x3e;1), linked by the relationships of the type: G&#x2212;Q&#x2261;1. mod n or G&#x2261;Qmod n. Among the m numbers obtained by increasing Qor its inverse modulo n to modulo n square, k&#x2212;1 times rank, at least one of them is different from &#xb1;g. Among the 2equations: x&#x2261;gmod n, x&#x2261;&#x2212;gmod n, at least one of them has solutions in x in the ring of modulo n integers.

Method, system, device for proving authenticity of an entity or integrity of a message

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.

Process for the broadcasting of programmes with progressive conditional

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.

Process for the broadcasting of conditional access programs permitting a

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.

Method of transferring a secret, by the exchange of two certificates

A method and system for authentication of accreditations and of messages with zero-knowledge proof and for the signing of messages, and a station for use in such system, in particular executed as a smart card station. Instead of using multiple accreditations and an iterative process of verification, use is made of a comprehensve accreditation (high exponent p) and a number D is drawn at random, which number is within the range between 0 and p-1. The operations of verifiction proceed by the computation of the D-th power of the inverse accreditation B. Application in particular, to smart cards and, more specifically, to bank cards.

Method and apparatus for authenticating accreditations and for

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.

Process for the broadcasting and reception of access title control

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.

Microprocessor intended particularly for executing the calculation

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:

Receiver having an interface with a sub-system

Pseudo-random binary sequence generators

The generator comprises three subassemblies, each comprising an adder and registers, said three subassemblies making it possible to provide three recursive sequences. Each sequence is dependent on variables constituted by initialization bytes. One state of the generator is defined by a particular combination of three sequences and each state determines an output variable, which is the desired coding or decoding byte.

Generator of encoding or decoding 8-bit bytes which can be used in a

Growing community of inventors

Bourgbarre-Saint Erblon, France

Louis C Guillou