Classifications

• • G—PHYSICS
  • G07—CHECKING-DEVICES
  • G07C—TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
  • G07C9/00—Individual registration on entry or exit
  • G07C9/00174—Electronically operated locks; Circuits therefor; Nonmechanical keys therefor, e.g. passive or active electrical keys or other data carriers without mechanical keys
  • G07C9/00309—Electronically operated locks; Circuits therefor; Nonmechanical keys therefor, e.g. passive or active electrical keys or other data carriers without mechanical keys operated with bidirectional data transmission between data carrier and locks
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R25/00—Fittings or systems for preventing or indicating unauthorised use or theft of vehicles
  • B60R25/01—Fittings or systems for preventing or indicating unauthorised use or theft of vehicles operating on vehicle systems or fittings, e.g. on doors, seats or windscreens
  • B60R25/04—Fittings or systems for preventing or indicating unauthorised use or theft of vehicles operating on vehicle systems or fittings, e.g. on doors, seats or windscreens operating on the propulsion system, e.g. engine or drive motor
• • G—PHYSICS
  • G07—CHECKING-DEVICES
  • G07C—TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
  • G07C9/00—Individual registration on entry or exit
  • G07C9/00174—Electronically operated locks; Circuits therefor; Nonmechanical keys therefor, e.g. passive or active electrical keys or other data carriers without mechanical keys
  • G07C2009/00753—Electronically operated locks; Circuits therefor; Nonmechanical keys therefor, e.g. passive or active electrical keys or other data carriers without mechanical keys operated by active electrical keys
  • G07C2009/00769—Electronically operated locks; Circuits therefor; Nonmechanical keys therefor, e.g. passive or active electrical keys or other data carriers without mechanical keys operated by active electrical keys with data transmission performed by wireless means
  • G07C2009/00793—Electronically operated locks; Circuits therefor; Nonmechanical keys therefor, e.g. passive or active electrical keys or other data carriers without mechanical keys operated by active electrical keys with data transmission performed by wireless means by Hertzian waves

Definitions

• the present invention relates to a method for identifying and authorizing the unlocking and / or starting of a motor vehicle, for an access system to a motor vehicle called "hands-free", as well as a device for identifying and associated authorization.
• FIG. 4 Such an access system is schematically represented in FIG. 4. It comprises a central unit C, arranged in the vehicle, which exchanges identification data with identification units B1, B2, B3. Each identification unit, commonly called a badge, is generally worn by a user. When a badge is recognized by the central unit C, this gives the authorization to unlock or start.
• FIG. 1 represents a communication diagram of a central unit C of such a system as well as the communication diagrams of the badges B1, B2, B3 dialoguing with the latter.
• the central unit C of the system After a predefined triggering action, for example when the user approaches a handle of the vehicle, the central unit C of the system
• the badge If a user, wearing a B1 badge, is near the vehicle, the badge detects this WU wake-up message and goes into listening mode.
• the central unit transmits a coded identification message CH. She then chooses the badge with which she will communicate to avoid that
• This step of the communication protocol consists of two phases generally called ANTI anticollision phase and SEL selection phase.
• the badges present around the vehicle send a message indicative of their presence.
• the badges present around the vehicle send a message indicative of their presence.
• the badges B1, B3, positioned near the vehicle each send a pulse A1, A3 indicative of their presence.
• the central unit selects a badge by sending a characteristic pulse SEL1 of the badge B1 that it has chosen.
• the other badge B3 goes into standby position.
• the central unit transmits, at regular time interval T, synchronization pulses S1, S2, S3.
• the selected badge B1 sends a coded response pulse IR1 which is an element of the response message REP.
• the synchronization pulses S1, S2, S3 make it possible to measure the processing time of the badge. This time measurement, generally called the anti-piracy step, makes it possible to inhibit unlocking when malicious people, equipped with pirate transmitter / receiver units, try to steal the vehicle.
• the central unit receives the pulse of the response message IR1 after a time greater than the processing time of the badge T due to the delay introduced by the processing time of pirate units.
• a communication method of this type does not have a sufficient level of security. Indeed, we can imagine that the pirate units mask the delay they introduce by eliminating the ANTI anticollision and SEL selection phases.
• hackers can trigger the communication procedure, and, after amplification, send WU wake-up messages and CH identification messages to the badge. Then, they cut the communication with the central unit and generate synchronization pulses. They receive the response pulses generated by the badge and send them back to the central unit, at the appropriate time. Consequently, the central unit cannot detect the presence of pirate units and the vehicle access system no longer has sufficient security.
• An object of the present invention is to provide an identification method having an increased level of security.
• the subject of the invention is a method of identifying and authorizing the unlocking and / or starting of a motor vehicle for a “hands-free” access system comprising a central unit exchanging messages of identification according to a method of communication with identification units, the method comprising:
• - a step of sending an indicative message from. the presence of the identification units having received the identification message to the central unit, - a step of sending a selection message by the central unit to select a particular identification badge to give a response to the identification message, characterized in that it includes a step of sending an additional identification message, and in that the step of sending a message indicative of the presence and / or the step sending a selection message is carried out between the step of sending the identification message and the step of sending the additional identification message so as to increase the security of the exchange between the unit central and identification units.
• the step of sending the additional identification message is immediately followed by the step of receiving the response message so that a delay introduced after the step of sending the additional identification message is always detected. by the central unit.
• the method according to the invention may also include one or more of the following characteristics: the additional identification message is a function of the identification message to increase the level of security of the communication method,
• the central unit is able to calculate part of the response message upon receipt of an identification message in order to reduce the duration of the communication process, the identification message is a random number generated by the central unit, - the process also comprising:
• a step of sending a response message from the particular identification unit to the central unit the response message being formed of at least two response pulses, the response pulses being emitted by the identification unit only after receipt of sync pulses so as to measure the processing time of the identification unit, characterized in that the pulses of syn chronization * are encoded so as to contain the additional identification message for decrease the duration of the communication process.
• the synchronization pulses are coded by modulation of their positions.
• the synchronization pulses are coded by modulation of the width of the pulses.
• these characteristics also make it possible to reduce the duration of the communication process so that the user no longer has to wait a few seconds before opening his door. This increases its comfort of use.
• the present invention also aims to identify and authorize or start a motor vehicle with an increased level of security.
• the subject of the invention is a device for identifying and authorizing or starting a motor vehicle comprising a central unit exchanging identification messages according to a method of communication with identification units, l the central unit being able to send an identification message to the identification units and a selection message to a particular identification unit, the identification units each being able to send a message indicative of their presence, characterized in what the device is able to send an additional identification message and in that the indicative presence message and / or the selection message is sent after sending the identification message and before sending the additional identification message so as to increase the security of the exchange between the central unit and identification units. 5
• the central unit transmits synchronization pulses to the particular identification unit and in that the particular identification unit transmits response pulses after reception of the synchronization pulses to measure the processing time of the particular identification unit, characterized in that the synchronization pulses are coded so as to contain the additional identification message in order to reduce the duration of the communication process.
• FIG. 1 represents a schematic view of a communication protocol according to the prior art, already described in the introductory part of the description,
• FIG. 2 represents a diagrammatic view of the communication protocol between a computer and identification badges according to the single embodiment of the present invention
• FIG. 3 which shows a schematic view of part of the communication protocol according to a possible improvement of the single embodiment of the present invention
• - in Figure 4 which shows schematically a hands-free access system.
• the communication method comprises an additional identification message CH2.
• this message is immediately followed by the step of receiving the response message REP. Consequently, if pirate units interpose between the badge B3 previously selected and the central unit C, the pulses of the response message IR1 are necessarily received with a delay corresponding to the processing time of the pirate units.
• the communication method according to the present invention has a higher level of security than a conventional communication method. Indeed, as the step of sending the additional identification message CH2 is directly followed by the step of sending the response message REP, no part of the communication method can be deleted to mask the delay time introduced. by pirate units.
• the additional identification message CH2 is necessary to give authorization to send the response message so that it cannot be truncated.
• It can, for example, contain a function of the encryption key essential for calculating the response message.
• the additional identification message CH2 also contains a coded function of the identification message CH so as to increase, by encryption, the security of the badge-vehicle computer communication.
• the identification message CH is either a random number generated by the central unit C, or a prerecorded number.
• the step of transmitting the identification message CH is carried out before the ANTI anticollision and SE selection phases.
• the badge microcontroller pre-calculates the REP response message during the anti-collision and selection phases so that after receiving the additional identification message (CH2), the response message is calculated more quickly. Consequently, the duration of the communication process is shorter.
• FIG. 3 schematically represents part of a communication diagram between the central unit C and a selected badge B1 according to an improvement of the present invention.
• This improvement makes it possible to reduce the length of the communication process and, consequently, to significantly increase the comfort of using a hands-free access system.
• the synchronization pulses S1, S2, S3 are coded so as to contain an identification message.
• the additional identification message CH2 can, for example, be transmitted simultaneously with synchronization. Coding can be carried out by modulation according to the width of the synchronization pulses or by modulation according to the position of the pulses.
• the synchronization and identification information is contained in the transmission of pairs of pulses S1, S1 ', S2, S2', S3, S3 '.
• a pair of pulses consists of a first S1 and a second pulse S2.
• the first pulses S1, S2, S3 are always sent at constant time interval T. They thus form the synchronization of the signal.
• the second pulses S1 ⁇ S2 ', S3' contain the additional identification message CH2.
• the pulses S1 'and S3' sent after a time t1 defined with respect to the emission of the first pulses S1 and S3, code for information corresponding to a 1.
• the badge After receiving a pair of pulses S1, S1 ', the badge sends a pulse of the response message IR1 during the period T. If the central unit does not receive a response during the time T, the central unit stops the communication process. Thus, the anti-piracy function is always performed. As in a conventional communication method, the response pulses IR1, IR2 are coded. We can for example choose to send an impulse
• IR1 to code information 1 and do not send a pulse IR2 to code information equal to 0. Coding can also be carried out by the width of the pulses or by modulation of their positions.
• the same antenna is used for reception and transmission of messages.
• This antenna is connected by a switch on the one hand to a transmission amplifier stage, and on the other hand to a reception amplifier stage.
• a microcontroller controls the switching frequency of this switch.
• the methods of communication of the badge B1 and of the computer C comprise alternately steps of transmission Tx and steps of reception Rx of the data of the same period, but in phase opposition.
• the badge After receiving a pair of pulses, the badge goes into Tx transmission mode and sends a response pulse.
• the central unit switches to RX reception mode.
• the communication method makes it possible to exchange data bit by bit, at the same frequency, for example on radio frequency, at frequencies of 315, 434 or 868 MHz.
• the first pulses S1, S2, always perform the synchronization function.
• the badge needs this synchronization to start its reception phase at regular time intervals and to obtain an accurate measurement of the distance between the badge and the central unit. Thanks to this synchronization, the communication process is faster and more efficient.
• the badge and the central unit can also each comprise two antennas. In this case, one antenna is dedicated to sending messages and the other antenna is dedicated to receiving messages.

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• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Lock And Its Accessories (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 2001
  • 2001-08-23 FR FR0111278A patent/FR2828967B1/fr not_active Expired - Fee Related
• 2002
  • 2002-08-13 WO PCT/EP2002/009062 patent/WO2003019481A1/fr active Application Filing
  • 2002-08-13 JP JP2003523467A patent/JP2005501189A/ja active Pending
  • 2002-08-13 US US10/487,499 patent/US6977581B2/en not_active Expired - Fee Related
  • 2002-08-13 EP EP02796229A patent/EP1421561A1/de not_active Withdrawn

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