FR2782402A1 - Access control between a portable electronic key and fixed electronic lock, uses asymmetric half periods for uni-directional and bi-directional transfer of electrical signals between key and lock - Google Patents

Abstract

The electronic lock and key comprises a power source on the key (1), which also has a computer, and a transmitter. The lock has a central lock processor and a transmission-reception module. The key also has a module for generating a power signal, a key transfer circuit. the lock has a lock transfer circuit. both circuits allow two way information transfer and power transfer from the key to the lock.

Description

ACCESS CONTROL DEVICE

  BETWEEN AN ELECTRONIC KEY AND LOCK

  The present invention relates to an access control device between a key and an electronic lock.

  ques, or, more generally, between a porta-

  tif and a fixed object, provided with access control functions and playing the role of an electronic key and lock. Enclosure access control systems

  closed to protect and protect faithful values

  To date, numerous complaints have been made

  developments. This is particularly the case with regard to

  concerns mailboxes for which systems

  opening hours - mechanical closing then, more recently-

  electronic, for speakers

  protected, have been implemented.

  Among the electronic systems, some develop-

  in particular have proposed a process of

  the supply of the portable object, the key, from the fixed base, the lock and the protected enclosure, due to the possibility of integration of power sources

  electric at the fixed base, in the absence of pro-

  major technical problem relating to such integration.

  The aforementioned mechanical systems do not make it possible to provide a satisfactory degree of security. The degree of security is based, in this case, on the degree of complexity of manufacturing the key, which is capable of being reproduced. In addition, in the event of theft of such a key, the invalidation of the latter, or of a reproduction thereof, can only be achieved by an adequate modification of all the locks associated with this key. With regard to electronic systems, the process of remote supply of the key by the lock poses maintenance constraints, change or recharge of electrical energy resources, or implementation, integration of a source of electricity. electric energy

  level of the lock, in particular, when the number of locks

  rures is important as in the case of letter boxes

very urban, for example.

  The object of the present invention is to remedy the

  aforementioned drawbacks of mechanical and electro-

  prior art by the implementation of a provision

  Access control between a key and an electronic lock in which any presence of a source of electrical energy at the level of the electronic lock, if necessary of the fixed base of the support of this lock

  electronic, can be deleted.

  Another object of the present invention is, therefore, the implementation of an access control system between an electronic key and lock in which any periodic intervention to change or recharge an electrical energy source at the level of

  electronic lock can be removed.

  Another object of the present invention is also

  ment the implementation of an access control device between an electronic key and lock allowing, in connection with the power supply process of the device, the implementation of control protocols

high security access.

  Another object of the present invention is also

  ment the implementation of an access control device between an electronic key and lock allowing the implementation of an access control process by exchange of digital data between the key and the lock

  electronic, in the absence of any electrical contact

  be the electronic key and lock.

  Another object of the present invention is finally the implementation of an access control device between

  an electronic key and lock in which the pro-

  the electrical power supply to the device is stopped if there is no electrical contact between

  the electronic key and lock.

  The access control device between a key

  and an electronic lock, object of this invention

  tion, this electronic key comprising at least one source of electrical energy, a logical key calculation unit, a module for transmitting reception of key access control signals and this electronic lock comprising at least one logical calculation unit and a transmission module - reception of lock access control signals for the implementation of a security protocol

  access control between this key and this electric lock

  is remarkable in that, on the one hand, the electronic key further comprises a generator module of a

  power signal supplied by the electric power source

  stick and controlled by the key calculation logic unit and a key transfer module of the key and lock access control signals and of the power signal,

  and in that, on the other hand, the electronic lock comprises

  additionally carries a door lock transfer module

  key and lock and access control gnaux

  general power and a module for storing the electric energy carried by the power signal, which ensures the unidirectional transfer of the electric energy carried by the power signal from the electronic key to the electronic lock and the bidirectional transfer of key access control signals and

  lock between the electronic key and the electric lock

  tronic. The access control device between a key

  and an electronic lock, object of this invention

  tion, finds application in the production industry and

  management of fiduciary security coffers, including

  of mailboxes, and access control of

high security in general.

  It will be better understood on reading the description

  tion and observation of the drawings below, in the-

  which: - the figure represents, in the form of a functional diagram, a general view of the control device

  of access between an electronic key and lock,

  form to the object of the present invention; - Figure lb shows, by way of first

  nonlimiting example, a sequential diagram of the process

  sus supply of the lock by the electronic key then bidirectional transfer of data between the key and the electronic lock in a device according to the object of the present invention; - Figure 2a shows a variant implementation of the access control device between a key and

  an electronic lock, in accordance with the subject of the pre-

  invention, in which a watch function of the

  electronic lock is ensured by an auxiliary source

  bond of electrical energy integrated in the electro- lock

  picnic; - Figure 2b shows, as a second

  nonlimiting example, a sequential diagram of the process

  the lock is supplied by the electronic key

  in the case of the existence of a watch function al-

  rented to the electronic lock, in accordance with the embodiment of Figure 2a; FIG. 3a represents a time diagram of the operations of unidirectional energy and bidirectional transfer of data between the electronic key and lock in connection with the waveform of the signal

  power generated by the electronic key, these operations

  tions which may correspond to those executed according to the sequential diagram represented in FIG. 1b; - Figure 3b shows a time diagram of the unidirectional and bidirectional data transfer operations between the electronic key and lock in connection with the waveform of the signal

  power generated by the electronic key, in a

  preferential implementation in which these operations are alternated; - Figure 4a shows a perspective view of an electronic key, according to the subject of this

  invention, in a preferred hardware embodiment

  non-limiting profit; - Figure 4b shows a perspective view

  an electronic lock, in accordance with the subject of the pre-

  invention, in a preferred nonlimiting material embodiment; - Figure 4c shows a partial view of the

  access control device between a key and a service

  electronic lock, in accordance with the object of this invention, when the electronic key and lock are brought together for an attempted access; - Figure 5a shows an electrical diagram of

  all the functional modules of the electronic key

  that in an embodiment given by way of nonlimiting example; FIG. 5b represents an electrical diagram of

  all the functional modules of the electro- lock

  nique in an embodiment given by way of nonlimiting example; FIG. 5c represents, by way of illustration, an image of the waveform of the power signal in unidirectional power transfer mode between the electronic key and lock; - Figure 6a shows a flowchart relating to an access control protocol between a key and a

  electronic lock constituting a device

  form to the object of the present invention;

  - Figure 6b shows, purely by way of illustration -

  trative, a specific mode of implementation of the protocol

  of access control, object of the invention, as shown

felt in Figure 6a.

  A more detailed description of a

  access control between a key and an electronic lock

  ques, according to the object of the present invention, will now be given in connection with Figures la and lb. As shown in FIG. La, the electronic key 1 comprises at least one source of electrical energy 0la, this source consisting for example of a storage battery with which is associated a battery management module, this management module able

  present, in a manner known per se,

  more or less sophisticated energy management con- tions

  held in the storage battery. For this reason,

  the battery management module does not

  ra not described in detail in this specification

cription.

  The electronic key 1 also includes a mo-

  dule of transmission - reception 12 of key access control signals. This module 12 can advantageously comprise a module for transmitting the key access control signals and a module for receiving the lock access control signals, these signals being transmitted digitally, as well as it will be described in more detail

  later in the description. By convention,

  key access control signals designate the access control signals emitted by the key to the lock and the lock access control signals designate the access control signals emitted by the lock to the key. The electronic key 1 finally comprises a logical key calculation unit, bearing the reference 11, this logical unit being responsible for controlling all of the

  electronic key operating operations.

  As also shown in FIG. La, the electronic lock 2 comprises at least one logic unit

  for calculating the lock, bearing the reference 21, and a mo-

  transmission / reception unit 22 of lock access control signals. Conventionally, the logical unit

  calculating lock 21 also makes it possible to control all

  the operating operations of the electric lock

  tronic 2. Thus, under the respective control of the logical calculation unit li and the logical calculation unit 21 of

  electronic key and lock, transmission module

  sion - reception 12 of key access control signals, the transmission module - reception 22 of lock access control signals, allow the implementation of an access control protocol between the key and the

  electronic lock 1, 2 above.

  With reference to the same figure la, it is indicated that the access control device, object of the present

  invention, further comprises, at the level of the electric key

  Tronic 1, a module generating a power signal,

  bearing the reference 13, this generator module being powered

  mented by the electrical energy source 1o and which can, of course, be controlled by the logical key calculation unit 11. Thus, all of the functional modules for managing the battery 10, transmission - reception 12 of

  key access control signals and power generator

  sance 13 is connected by a link to the logic unit of

  calculation of key 11 and controlled by the latter.

  In addition, as shown in the same figure

  la, the electronic key 1 comprises a trans-

  key fert, bearing the reference 14, signals of con-

  key and lock access hole as well as, in accordance with a particularly advantageous aspect of the

  access control device, object of this in-

  vention, of the power signal generated by the module

  generator 13. More specifically, it is indicated that the aforementioned key transfer circuit 14 is connected, on the one hand, to the module generating the power signal 13

  and, on the other hand, to the transmission module - reception of si-

  12 key access control general conditions

  which will be explained in more detail later.

rement in the description.

  As is also shown in FIG. 1 a, the electronic lock 2 comprises, for the purpose of constituting the access control device, object of the present invention, a circuit for transferring lock of the access control signals of key and lock and the aforementioned power signal. This transfer circuit

lock number 24.

  Finally, the electronic lock 2 also includes

  a module 25 for storing and therefore recovering the electrical energy conveyed by the

  power signal. Lock 2 can, as shown

  felt in a nonlimiting manner in FIG. la, being in

  additionally provided with a clock signal recovery module

  box, bearing the reference 23, this clock signal can be recovered from the power signal, as will be described in a nonlimiting manner later in

the description.

  Of course, the functional modules constitute

  of the electronic lock 2, that is to say the module for transmitting reception of the access control signals from the lock 22, the module for storing electrical energy and, where appropriate, the recovery module 23, are connected via a link to

  the logic unit for calculating the lock 21. As regards

  identifies the lock transfer circuit 24, it is indicated that the latter is of course connected, on the one hand, to the transmission - reception module 22 of the lock access control signals, and, on the other hand, to the module 25 for storing electrical energy as well as, where appropriate, module 23 for recovering the clock, as will be described in more detail later

in the description.

  It is thus understood that the access control device, object of the present invention, allows the implementation of an access control protocol in which are carried out, on the one hand, a unidirectional transfer of electrical energy conveyed by the power signal from the electronic key to the electronic lock, and, on the other hand, the bidirectional transfer of the

  key and lock access control between the electric key

  door 1 and electronic lock 2, as it will be

described below.

  Advantageously, without limitation, as shown in FIG. La, the transfer circuit 14 of

  key and the lock transfer circuit 24 are advantageous

  suitably constituted by at least one primary winding

  and at least one secondary winding of a transformer.

  In such conditions, the primary windings, noted

  L1, and secondary, noted L2, are then coupled electroma-

  genetically when putting the electric key in the presence

  door and electronic lock, this pre-

  sence being performed to make an access attempt.

  The operating mode of the access control device

  ces, object of the present invention, as shown in

  figure la, can be illustrated, by way of non-limiting example

  tative, as shown in Figure lb. We note in par-

  particular that in the case of the implementation of the access control device, object of the present invention, and in a simplified embodiment, the lock 2 has no permanent source of electrical energy, the entire transfer of electrical energy of the key

  electronic to electronic lock for sub-

  to meet the necessary electrical energy needs, in order to conduct the access control protocol in accordance with the object of the present invention. In such a case, as shown in FIG. 1b, the unidirectional transfer

  electrical energy carried by the power signal

  from the electronic key to the electronic lock

  that, this power signal being denoted PS, can be

  performed prior to the bidirectional transfer of si-

  key and lock access control channels between the electronic key 1 and the electronic lock 2. In such a case, the transfer of a quantity of electrical energy sufficient for the implementation of the control process

  access proper, conducted during the two-way transfer

  data, then appears as a new condition

  stop implementing the entire protocol

  access control in accordance with the subject of this invention

  tion. Consequently, in FIG. 1b, the operations of unidirectional transfer of energy from the key to the lock and then of bidirectional transfer of data between

  the electronic lock and the electronic key, and

  are represented in figure lb by two

  substantially distinct successive stages.

  However, as shown in FIG. 2a, a more elaborate embodiment of the access control device, object of the present invention, can consist in providing, at the level of the lock 2, a source of energy.

  auxiliary electric, bearing the reference 20. Of a ma-

  In general, this source of auxiliary energy,

  calf of lock 2, ensures a standby function of the latter. To this end, the auxiliary electrical power source 20 is adapted so as to allow, at least, the supply of the logic unit for calculating

  lock 21 as well as the reception part of the transmission module

  sion - reception 22, in order to allow the conduct of the standby function under the authority of the logic unit of

lock calculation 21.

  In FIG. 2b, a diagram has been shown

  essentials of an access control protocol implemented

  by the access control device, object of the pre-

  invention, represented in FIG. 2a, in the case of the existence of a standby function at the level of the lock 2. In accordance with the above-mentioned figure, the bidirectional transfer of the key and lock access control signals, or at least part of these, between the electronic key 1 and the electronic lock 2 is carried out prior to the unidirectional transfer of the electrical energy conveyed by the power signal PS from the electronic key 1 to the electronic lock 2. As d non-limiting example, during the standby function of lock 2, and on attempt to access the electronic key 1, lock 2 can thus transmit to

  the electronic key 1 an identification request message

  tion, noted RID. In response to the identification request message

  above, the electronic key 1 can transmit a MID identification message to lock 2 and, on

  identification criterion satisfied with this identification message

  lock, lock 2 transmits in response a message from

  identification response to electronic key 1, this mes-

  wise being denoted ACKID in Figure 2b. This acknowledgment message can then allow the conduct of the

  unidirectional energy transfer process by the

  signal PS intermediate between electronic key 1 and

  the electronic lock 2. Under these conditions, the trans-

  unidirectional energy fert is realized conditional-

  ment to the success of the at least partial bidirectional transfer of data during the standby function. Following the

  Unidirectional energy transfer, the con-

  access hole, in accordance with the subject of this invention

  tion, can then be continued between the lock

  electronic 2 and the electronic key 1 according to a process

  above specific access control consisting of a success-

  transfer of message exchanges, encrypted or not, the electronic key 1 and the electronic lock 2 being able to be provided with encryption and decryption means, as will be described in more detail later

in the description.

  The operating modes as illustrated in figure

  2a and 2b sequentially will be explained now.

  in connection with FIGS. 3a and 3b respectively,

  the aforementioned figures making it possible to introduce a definition

  more detailed temporal tion of the different sequences

implemented.

  In FIGS. 3a and 3b, there is shown, in a particularly advantageous embodiment, the power signal PS, this signal, in this embodiment

  advantageous, being constituted by a periodic signal asy-

  metric and therefore comprising substantially a de-

  mid period of high amplitude, amplitude denoted M, and a

  half period of low amplitude, noted m.

  In general, and in the case of an operating mode corresponding to the access control device

  as shown in FIG. 1 a, this operating mode

  corresponding to that shown in FIG. 1b, the unidirectional transfer of energy between the electronic key and lock can advantageously be carried out over a plurality of half periods of high amplitude of the power signal PS, the unidirectional transfer step

  energy key / lock with the reference 1 on the figure

  gure 3a. The number of successive half amplification periods

  high studies during which the unidirectional transfer

  of energy between the electronic key 1 and the electric lock

  Tronic 2 is performed can then be calculated based on

  tion of the total energy required to conduct the

  Bidirectional data transfer between the electronic key

  pic 1 and electronic lock 2 for implementation

  of the access control protocol proper by trans-

  bi-directional key / lock data fert, as well as re-

  presented in figure lb, this step bearing the reference 2

in Figure 3a.

  In the above-mentioned figure, it will be noted that, during the step of bidirectional data transfer between the

  electronic key and electronic lock, transmission

  power signal PS is represented in point

  tillés. Such a transmission can indeed be maintained during the step of bidirectional transfer of data between the key and the lock, step 2. In fact, the simultaneous transmission of the power signal PS and of data between the electronic key and lock can

  be carried out without difficulty insofar as the

  signal level caused by the transmission of the power signal PS does not interfere with the bidirectional transfer of

  data. Under these conditions, the electrical energy trans-

  setting the electronic lock 2 can thus be maintained at a substantially constant level for the conduct of the entire access control protocol, object of the present invention. However, the data is transmitted over several consecutive periods because the frequency

* modulation must be low compared to the frequency

  teuse. However, a preferred mode of implementation

  of the operating method of the access control device,

  jet of the present invention, can also be conducted,

  as shown in connection with Figure 3b.

  In this mode of implementation, the unidi-

  of the electrical energy carried by the power signal PS and the bidirectional transfer of the key and lock access control signals can be

  alternately performed on substantially half a

  high amplitude period and substantially half a low amplitude period respectively. Under these conditions, step 1 of unidirectional transfer of key / lock energy is in a way distributed over all the half periods of high amplitude of the power signal PS, while step 2 of bidirectional transfer of

  key / lock data is itself distributed on the

  half periods of low amplitude, the stages of transfer

  unidirectional key / lock energy and bi-transfer

  directional data key / lock 2 then being imbricated

  quées as shown in Figure 3b, and performed al-

  ternatively. An access control protocol

  corresponding will be described in more detail later.

laughingly in the description.

  A more detailed description of a key and

  electronic lock allowing the implementation of an access control device, in accordance with the object of the present invention, will now be given in conjunction with

  FIGS. 4a and 4b in a material embodiment

non-limiting rielle.

  As shown in FIG. 4a, the electronic key can be produced in the form of a block in

  molded material, bearing the reference B1, the material block

  molded riau for example injected around a plate

  printed circuit board, marked PIC1, on which the various functional modules previously mounted

  mentioned in the description in conjunction with the figures

  la or 2a, these functional modules bearing for this reason

  its the same references and being represented, as well as

  the printed circuit board, dotted. We note in particular that the block B1 constituting the body of the key

  electronics can then be provided for example with an on / off switch, denoted ON / OFF, as well as with a serial or parallel interface, denoted PI, this serial or parallel interface being connected, by a link by BUS, to the logical key calculation unit 11, in order to

  allow for example the programming of the electronic key

  aforementioned pic. This programming can also be carried out via the primary winding of the transformer. It is understood in particular that with the logical key calculation unit 11, constituted for example by a microcontroller, are associated the conventional elements such as random access memory and read only memory, not shown.

  at drawings. Specific programs such as program-

  mes of conduct of the access control protocol in accordance with the object of the present invention, can be stored

  in the ROM. The electronic key 1 includes no-

  especially the power signal generator module PS,

  referenced 13, and of course the transmission module-

  reception of key 12, the assembly being controlled by the unit

  of key calculation 11. With regard to the operating mode

  roof of the assembly and the concept of piloting by the logical unit of calculation of key 11, it is indicated that the setting in

  opens the device access control protocol, ob-

  jet of the present invention, can be achieved by sim-

  full commissioning of the power supply for all of the aforementioned functional modules. In particular, it is indicated that the operation of the module generating the signal

  power 13 triggered by this start-up can

  continuation to be free, that is to say in the absence of effective control of the logical unit of calculation of key 11, thus

  that it will be described later in the description. In

  in such a case, however, the power signal generator module is not connected to the logic unit for calculating

key.

  Regarding the key transfer circuit 14 of the key and lock access control signals,

  it indicates, as shown in Figure 4a above

  tee, that it can be achieved by means of a coil 140 mounted on a sleeve 141 shown projecting in Figure 4a, this sleeve being located in the injected block B1, which provides adequate mechanical support of the assembly formed by the sleeve 141 and the winding 140. The connection of the winding 140 to the power signal generator module 13 and to the key transmission-reception module 12 is carried out by a wire connection, which

  is also embedded in the injected block Bl.

  Finally, and without limitation, the housing B1

  can be equipped with a trap door, noted TV, allows

  as long as access to the accumulator battery constituting the electrical energy source 10. The winding 140 is itself constituted by contiguous turns by means of an electrically insulated copper wire. The sleeve 141 is advantageously constituted by a magnetic material such

  than a ferrite rod for example.

  With regard to electronic lock 2, as well

  if shown in FIG. 4b, a comparable embodiment can be envisaged from a housing B2 in

  molded injected plastic material, this housing B2 being

  integrated into the mailbox or BL enclosure, access to which is reserved. The box B2 can, in the same way as in the case of FIG. 4a, be injected around a printed circuit board PIC2 comprising all the functional modules represented in FIGS. 1a or 2a, 21,

  22, 23 and 25, if applicable 24 and 20.

  A manufacturing method can then consist of mu-

  fix the PIC2 printed circuit board with a notch, no-

  ENC tee, in which the lock transfer circuit

  24 is mounted. In the same way as in the case of the fi-

  gure 4a, the key transfer circuit 24 is constituted by a winding with contiguous turns, which is fixed and maintained in the notch ENC and suitably connected to the functional modules 23, 25 and 22 previously mentioned

  in the description. The injection of the B2 housing allows

  then to obtain a compact block and a cylindrical cavity 241 can then be produced by suitable bore, subject to the usual precautions, in order to achieve a

  adapted cylindrical cavity. In addition, in the cy-

  lindrique 241 above, can then be inserted a hollow tube 242 constituting for the winding 240 constituting the

  transfer circuit 24 a sleeve which can be op-

  tionally conferred electromagnetic properties.

  The hollow tube 242 and / or the cavity can for this purpose be made of a magnetic ferrite material such as

  sleeve 141 relative to FIG. 4a.

  Of course, other embodiments, both of the electronic key and of the lock, can be envisaged. In particular, the male character of the key, represented by the protruding sleeve 141 in FIG. 4a, and the female character of the lock, represented by the cavity 241, allowing the key and the

  lock for attempted access, may be in-

  poured or even neutral, ie flat. Other mo-

  non-limiting embodiments can also be envisaged. In particular, the sleeve 141 and the cavity 241, as well as the hollow tube 242, can have a

  section of revolution, circular, or polygonal.

  In an experimental embodiment, the electrically insulated copper wire, allowing the winding 140 and the winding 240 of the key and lock transfer circuits, was a copper wire with a diameter of 0.5 mm, the sleeve 141 had a total length of mm, the part of the protruding sleeve emerging from the housing B, over a length of 25 mm. The diameter of the assembly constituted by the sleeve 141 and the winding 140 had

a value of 11 mm.

  As regards the cavity 241, this being provided with the hollow tube 242 as shown in FIG. 4b,

  this cavity had an internal diameter dimension

  11 mm laugh, allowing the insertion of the protruding sleeve

of the same dimension.

  In particular, the implementation of the cavity 241

  is not limited to an implementation by boring. Indeed-

  fet, it is also possible to perform the injection of the material of the block B2 around the wafer

  PIC2 printed circuit through introduction into the bo-

  hoeing 240 of a rod of suitable diameter. Suppression

  of the rod then makes it possible to form the cavity 241 mentioned above.

  tee. This operating mode then makes it possible to adjust the thickness

  of injected material separating the winding from the cavity thus

  if carried out, which improves the coupling of the bo-

  hoes 240 and 140 when the key is brought into contact

and the lock.

  In Figure 4c, there is shown, in a sectional view, the relative position of the electronic key and the electronic lock when the key is put in

  presence of the lock to make an attempt to access

  these. We note in particular that the windings 140 and

  240 constituting the key transfer circuits, res-

  pectively lock, are opposite, the posi-

  tction of the latter being established accordingly. In addition, a specific, non-limiting embodiment

  may consist, at the level of the lock, of providing boxes

  separate hoes for the energy recovery module

  and for the transceiver module 22, these two mo-

  dules then being completely separated.

  A more detailed description of an embodiment

  advantageous position of the functional modules of the electronic key and lock will now be given in

connection with Figures 5a and 5b.

  As regards the electronic key 1, the source of electrical energy 10 can be constituted by a rechargeable battery. This battery can be a

  battery of the type of those intended for portable telephones

  cables, with a nominal voltage of 4.8 V and a capacity of 600 mAh. The storage battery can be recharged by electrical contact from external terminals accessible, for example at the parallel interface, or, if necessary, via the contactless connection of the key, ie via the transfer circuit 14. The battery management module can

  then manage the recharging operation.

  Regarding the starting and stopping of

  the electronic key, it indicates that the rear button

  ON / OFF ON / OFF has the effect of supplying electronic circuits other than any circuits which are permanently supplied, such as a real time clock for example. Another solution may consist in implementing an automatic start / stop following the automatic detection of a lock by the key. A

  such function can be realized, by electro- detection

  magnetic of the presence of the key and a service

  rure for example. Under these conditions, the battery management module, represented in FIG. 1a or 2a,

  may incorporate such a detection system in order to

  der to the on / off of the battery to ensure the supply of the whole. The aforementioned function can also be implemented by detecting a significant variation in the electrical impedance seen at the terminals of the winding of the key, during contacting

  electronic key and lock.

  With regard to the logical unit of calculation of

  key 11, it is indicated that it consists of a mid

  crocontroller, or microprocessor, with which is associated a

  external oscillator of the quartz oscillator type for example-

  full. Such an associated system, known as such, is not

  ra not described in detail nor shown for this reason

  in the drawings. The quartz / micro oscillator assembly

  controller, from an oscillation frequency of 4

  MHz, allows to deliver a so-called carrier signal by di-

  frequency vision at 250 kHz for example. This carrier is used for the transmission of the electrical energy of the key

  to the lock and, in particular, to the constitution of the si-

general PS power.

  Regarding the signal generator module

  of power 13, as shown in FIG. 5a, this

  this includes a current amplifier device

  killed by two bipolar transistors Q1 and Q2 connected in tracking elements between the supply voltage VCC and

  the reference voltage noted 0, the bases and emits them-

  tors of these transistors being connected together, these transistors being of opposite conduction type. The base

  of the aforementioned transistors receives the pre-carrier signal

  previously mentioned, issued by the key calculation logic unit 11 and delivers a current amplified signal, which corresponds substantially to a square signal at the frequency of 250 kHz. The power module 13 also includes

  a FET type MOS transistor, referenced M1, connected in-

  tre the reference voltage and the winding 140, denoted L1, of the transfer circuit 14 of the power signal PS and of the key and lock access control signal. The MOSFET transistor M1 is connected in series with the above-mentioned coil L1 and the gate of the transistor M1 is connected to the signal

  amplified carrier delivered by bipolar transistors

  res Q1 and Q2. The drain electrode of the MOSFET transistor M1 is thus connected in series with the winding constituting the inductance L1, which itself is connected in series with a low value load resistor R1 connected to

the supply voltage Vcc.

  More specifically, it is indicated that the resistor R1 as represented in FIG. 5a constitutes a load resistor for the MOSFET transistor M1 constituting an element of the transmission part of the transmission-reception module 12 of the electronic key, thus that it will be described in more detail later

in the description.

  The command applied to the gate electrode of the

  MOSFET M1 transistor ensures al-

  ternative of the latter, this transistor causing the pas-

  wise of a current in the inductor L1, which, when it is in the presence of the corresponding coil 240 of the lock, in fact constitutes a transformer with

  this one. The blocking of transistor M1 then causes the ap-

  appearance of an overvoltage on the drain electrode of this

  last and, consequently, on the windings of the trans-

  trainer previously cited. MOSFET M1 is

  chosen so as to present a series resistance in con-

  duction less than 0.5 Ohm, a breakdown voltage of the order of 100 V and an admissible peak current of the order of 25 A, in order to ensure proper operation at

switching transients.

  When the M1 MOSFET transistor is conductive, the

  voltage across the transformer primary, i.e.

  say of the inductance L1, is close to the supply voltage

  mentation Vcc whereas, during the rupture of the conduc-

  tion, the overvoltage that appears on this same inductor

  L1 is transmitted to inductance L2 constituted by the coil

  swims 240 at the lock. The voltage received preci-

  tee, at the level of the lock, is therefore asymmetrical and the amplitude generated during the blocked alternation of the MOSFET transistor M1 is greater than that generated during

of its alternation in conduction.

  Bidirectional transmission of signals from

  key and lock access control between the electric key

  and the electronic lock is carried out, at the

  calf of electronic key 1, thanks to the transmission part

  and at the reception part of the transmission module 12-

  reception, and, at the electronic lock 2,

  thanks to the transmission part and the reception part of the mo-

  dule 22 of transmission-reception. In particular, in the embodiment described in connection with FIG. 5a, the

  transmission part of this module 12 comprises, in addition to the resis-

  tance R1 already mentioned, a MOSFET transistor, referenced

  M2, of which the drain and source electrodes are connected

  ted in parallel on the aforementioned resistor R1. The elect

  gate trode of the MOSFET M2 transistor is controlled by a current amplifier, with a structure similar to that

  described above, and constituted by the bi- transistors

  poles Q3 and Q4 with a common base electrode

  batched by the output of the logical calculation unit 11,

  that is to say from the microprocessor or microcontroller.

  This output then delivers a signal representative of the bits of the key access control signals, that is to say of the access control signals emitted by the key towards the lock. The common point of the transmitters of the Q3 transistors

  and Q4 delivering a signal amplified with representative current

  tif of the transmission of the data, that is to say of the key access control signal, then controls the gate electrode of the MOSFET transistor M2. Under these conditions, the data signals, i.e. the control signal

  key access, causes, via the ampli

  current ficitor constituted by the transistors Q3 and

  Q4, switching of the MOSFET M2 and, consequently

  quence, an all-or-nothing modulation of the load,

  that is to say of the resistance R1, seen by the inductance L1.

  The aforementioned inductance constituting the primary circuit of

  transformer is then charged by a varia-

  ble according to the binary information transmitted. This process has the effect of modulating the power output impedance seen by the transformer primary, this

  modulation type being close to amplifier modulation

  study of the carrier. The M2 MOSFET transistor can present

  ter characteristics similar to those of the MOSFET transistor M1, with however a lower maximum admissible current not exceeding one ampere. Under these conditions, the transmission bit rate is 9,600 baud. The binary information of the access control signal from

  key are coded into a Manchester code for example the dice-

  useful bit of information then being 4,800 baud. In

  concerning the reception part of the transmission module -

  reception 12, it is indicated that this part is directly

  connected to the common point of the resistor R1 and the

  ductance L1 previously mentioned. This common point de-

  delivers a received signal, i.e. the control signal

  lock access when this is issued by the service

  rure. The signal received is the image of the current consumed in

  lock 2, i.e. in fact the image of the module-

  load brought into the lock similarly

  ble to that which is carried out at the level of the key

  previously described in the description. The receiving part

  tion of the transceiver module 12 is connected by

  through a capacity C1 at the common point R1L1 pre-

  cited and a Qs, Q6 and R2, R3 inhibition circuit. A resistor bridge R4, R6, R7 and a decoupling capacity C2 make it possible to fix the DC component of the received signal

  at the value half of the supply voltage Vcc. The en

  seems capacitor C1 / polarization bridge, constitutes a high pass filter. The signal received after alignment at half the supply voltage via the

  aforementioned resistance bridge is then subjected to a wire-

  trage by means of a filtering stage constituted by an operational amplifier A1 constituting, with the resistors R5, R8 and the capacitors C3 and C4, a low-pass filter of the second order of the BUTTERWORTH type. The aforementioned filtering stage is followed by a voltage amplifier

  gain 10, i.e. 20 dB, formed by an operational amplifier

  tional A2 and by resistors R9 and RIo, a capacity

  C5 being connected in parallel on the resistor Rjo. In-

  end, an A3 formatting comparator and a feedback bridge

  sistances formed by resistors R4, R6, R7 and the

  decoupling capacity C2 to constitute a level of re-

  ference according to the received signal, allows to deliver a bit stream to the reception input of the microcontroller,

  that is to say of the logical unit for calculating key 11.

  The idle state is fixed by a voltage offset generated

  dré by the resistive bridge Rjl, R12.

  The input impedance of the filtering stage is taken sufficiently high not to weaken the useful signal. Capacities C3, C4 and resistors R5, R8 in the filtering stage, give the latter a structure

  low-pass type with cut-off frequency 50 kHz. The re-

  Sistances Rll and R12 ensure a shift of the signal to the reference voltage. Comparator A3 is

  chosen so as to require a low supply voltage

  tation, 3 V, and low consumption. The exit

  created by the latter can then be directly connected

  at the input of the microprocessor, or microcontroller, consisting

  of the logical unit for calculating key 11, the resis-

  tance R12a constituting a bias resistance of the

comparator output.

  With regard to electronic lock 2, as well

  if as shown in FIG. 5b, the recovery modules

  tion of the power supply 25 and the reception part of the transmit-receive module 22 of the lock 2 are connected to the winding constituting the transfer circuit 24,

  key and lock access control signals,

  ie the inductance L2 mentioned in the description

  previously. Regarding the recovery module

* of energy 25, as shown in Figure 5b above

  energy is restored from the winding

  condaire L2 via a diode bridge, no-

  tees D1, D2, D3 and D4, mounted symmetrically. The diode bridge is referenced 250. The common point of the diodes D1, D2 is connected to a first terminal of the winding L2, the common point of the diodes D2 and D3 is connected to the reference voltage and the common point of the diodes D1 and D4

  delivers, from the transformer secondary,

  ie from winding L2, a rectified voltage corresponds to

  corresponding to that generated by the switching of the

  MOSFET transistor M1 on the primary winding L1.

  The common point of the diodes D3 and D4 is connected to a resistor R15, load resistor, this resistor being itself connected to the reference voltage by a

  bipolar transistor Qa, which is at rest not conductive-

  tor. At rest, blocking of transistor Q7 causes that

  of the transistor Qs. The other terminal of the second winding

  Daire L2 is also connected to the common point of the two

  diodes D3 and D4. It is also connected to a resistor

  tance R15a intended to fix the potential of the winding

  L2 when transistor Q8 is blocked.

  Finally, the common point of the diodes D1 and D4 delimits

  The rectified voltage is connected to the input of a voltage regulator 251, which makes it possible to deliver a

  regulated voltage, denoted Vreg, intended to supply the

  tation of all the electronic lock circuits

  that 2. The capacitors C7 and C8 are capacitors of high capacity with regard to the carrier frequency and

  respectively of specific cutoff frequency allows

  both to ensure energy storage at the entrance and the sta-

  stabilization of the voltage at the output of the regulator

tension 251.

  When transmitting the power signal PS by

  through the transformer formed by the reels

  Lements L, and L2, the two half-waves of the signal are then used. The conductive state of the MOSFET transistor M1 generates a voltage of the order of 8V across the terminals of the

  condaire L2, this voltage source having an impedance

  weak output dance. The blocked state of the MOSFET transistor M1 generates a higher voltage, but the Thévenin generator equivalent to the terminals of the inductor L2 has

  then a higher output impedance.

  In general, as shown in FIG. 5c, the recovery of electrical energy from the power signal PS therefore takes place essentially

  during the high amplitude half period, this recovery

  80% energy ration can be achieved within 10%

  from the beginning of the duration of the half period of high ampli

  study due to the phenomenon of transient overvoltage

  generated by the switching of the MOSFET transistor M1. While figure 5c represents the tension developed on the

  drain of the MOSFET transistor M1, at the common point of the bo-

  bine L1 and the aforementioned MOSFET M1, the power signal PS can be represented from FIG. 5c

  by graphic anamorphosis, taking into account the tension

  continuous Vcc and temporal axis affinity due to the pre-

  resistance R1. However, as mentioned previously, the two alternations of the signal can be

  operated through the diode bridge 250, the diodes used

  sées being SCHOTTKY rectifier diodes for example-

  full. Due to the equivalent generator speed of each high and low voltage amplitude of the power signal PS, one of the alternations is comparable to a source of amplitude voltage and high output impedance and the other to a source. amplitude voltage and low output impedance. The regulator 251 can be chosen as a low waste voltage regulator in order to supply the regulated voltage Vreg, which can be

  socket equal to the voltage Vcc previously mentioned rela-

  for the supply of the electronic key 1.

  Regarding the transmission part of the module

  transmission-reception 22 of the lock, in addition to the resistance

  these load R15 and the bipolar transistor Q8 previously mentioned, it is indicated that the above-mentioned emission part circuit further comprises a bipolar transistor

  Q7 whose transmitter is connected to the delivered voltage

  gulated Vreg by the regulator 251. The transistor Q7 is

  mounted as a common transmitter via a resistor

  collector voltage R14 connected to the reference voltage

  rence. The base of the bipolar transistor Q7 then receives, via a resistor R13 the binary signal delivered by the logic unit for calculating the lock 21, this

  binary signal being representative of the data, i.e.

  say of the lock access control signal delivered by the electronic lock 2. The logic unit for calculating the lock 21 can be constituted by a microprocessor. The

  binary train delivered on the base electrode of the transis-

  tor Q7 then ensures, through the latter, the switching of the load resistor R15 to a midpoint of the diode bridge 250, that is to say the connection point of the diodes D4 and D3. When the load resistor R15 is switched, a current variation is

  then induced in the winding L1 of the electronic key

  than 1 through the transformer. This varia-

  tion of current is transformed into a variation in voltage

  sion on the load resistance R1 of the above-mentioned winding L1, that is to say at the input of the reception part 12 of the transmission-reception module 12, as shown in FIG. Finally, as regards the reception part of the transmission-reception module 22 of the lock, it is indicated

  that this part is connected to the common point of the winding

  Lement secondary L2 and the common point of diodes D3 and D4 of the diode bridge 250 via a diode D5, which has characteristics similar to those

diode D1.

  Indeed, the information transmitted by the electronic key 1 is perceived by the electronic lock 2 as an amplitude modulated signal. Consequently, the useful signal is not taken at the output of the diode bridge, common point of the diodes D1, D4 of the diode bridge 250, because this signal is distorted by the filtering and

  regulation associated with regulator 251, namely the

cited C7 and C8.

  On the contrary, as shown in FIG. B, the signal received is taken at the midpoint of the diode bridge 250 previously mentioned and in particular on the branch of the diode bridge 250 which rectifies the alternation of lower amplitude, this is ie the branch D1, D3 or D2, D4. This alternation corresponds to the conductive state of the

  MOSFET M1 switching transistor of the electronic key

  that 1. This alternation is chosen because it is not clipped by the rectification capacities of the lock, the capacities C7 and C8. Under these conditions, the alternation

  higher amplitude provides energy as a priority. Ain-

  if, the two asymmetrical half-waves are rectified, but as long as a too high current consumption by the lock 2 does not intervene, only the half-wave supplying

  the highest voltage is used to supply the

  mentation to the lock. Under these conditions, the alternation

  providing the lowest voltage can then be used

  set to receive the information delivered by the winder-

  ment L1 of the transformer primary, i.e. the

  key access control signal.

  However, when the current demand by the

  lock can no longer be satisfied by the four-

  the second branch of the diode bridge 250 then supplies current. The aforementioned operating mode may then no longer make it possible to ensure the separation of the supply of energy and of information by using the asymmetry of the amplitude of the signal of

PS power.

  Regarding the received signal, it is transmitted by the diode D5 to a processing chain. The processing chain, as shown in FIG. 5b, comprises a demodulation stage formed by the resistance

  R16, capacity C9 and resistance R17. This floor of de-

  modulation performs an amplitude demodulation at the frequency

  cutoff frequency of 50 kHz and acts as a low-pass filter. C10 is a link capacity. A circuit

  inhibition formed by the transistors Q5, Q6 and the

  resistors R2, R3, similar to the inhibition circuit of FIG. 5a can also be inserted between the capacitor C10 and the common point of the resistor R16 of the capacitor

  C9 and resistance R17, as will be described in detail

  more detailed later in the description.

  A polarization bridge made up of resistors

  tances R18, R20, R21 and the decoupling capacity Cll at the reference voltage makes it possible to adjust the average value of the

  signal at the value half of the regulated supply voltage

  Vreg. In connection with capacitance C10, the aforementioned stage introduces a capacitive bond and constitutes a high-pass filter. For this reason, it is necessary to respect in the binary message an alternation of high and low level, the coding of Manchester coding type being

] 0 then used.

  The aforementioned processing chain also includes a second order 50 kHz low-pass filtering stage produced by means of the operational amplifier A4, resistors R22 and R19 and capacitors C12 and C13. This filtering ensures rejection of the carrier to

  250 kHz while maintaining the shape of the square wave.

  The filtering stage produced constitutes a GOAL- filter

TERWORTH.

  The aforementioned filtering stage is followed by an ampli

  reversing ficator consisting of an operational amplifier

  tional A5 and by resistors R23, R24, capacity C15.

  A resistance-capacitance filter formed by resistors R25, R26 and capacitance C14, provides an offset

  in voltage allowing to assign to a comparison stage

  sound, constituted by comparator A6, a stable state in

  no signal, due to the intro voltage offset

  duit by the aforementioned resistive bridge. At rest, tension

  applied to the positive input of comparator A6 is felt

  approximately equal to half of the supply voltage, that is to say the regulated voltage Vreg. The offset and comparison stage delivers at its output to the microcontroller constituting the logic calculation unit 21 of the lock, the

  key access control signal received by the lock.

  As regards the clock recovery module 23, it is indicated that it can be introduced into the lock in order to generate a time base punctuating the work of the constituent microcontroller

  of the logical calculation unit 21. We understand in particular

  link that this time base is obtained by detection of the carrier, that is to say of the power signal PS. This

  module can be made from a worm loop

  phase rust on the fundamental frequency of the power signal generated by the electronic key 1

  in order to generate a frequency multiple of the latter.

  In the case of the integration of a clock recovery module 23 in the lock 2, it is then possible to delete the quartz oscillator normally associated with the logic calculation unit, that is to say to the microcontroller

or to microprocessor 21.

  The embodiment of the key and

  lock, as shown in FIGS. 5a and 5b, have

  put, thanks to the adapted choice of the physical parameters of the components, an optimum transfer of power and electrical energy, between the key and the lock, for an impedance brought down by the transformer constituted by the

  windings L1, L2 between 100 Q and 200 Q.

  under these conditions was equal to 0.76 for

  a transmitted power of 370 mW. Power values

  higher transmitted sance can be obtained.

  Finally, inhibitor circuits can be in-

  products to make the reception part of the key and the lock insensitive, the signals emitted by the key not being perceived by the latter, and vice versa

  for the lock, in order to decrease the turnaround time

  is lying. The turnaround time is defined as the duration

  minimum silence to be respected between the end of a broadcast-

  the start of a reception so as not to cause

  collision between corresponding messages. Thanks to the

  production of inhibition circuits, the return time

  ment is reduced from 500 ms to 25 ms. In such conditions, an uninterrupted dialogue between the key and the lock can be carried out. An inhibition circuit formed by the transistors Q6 and Q5 and the resistors R2, R3, can thus be introduced at the input of the reception part.

  of the transmit-receive module 12 of the respective key-

  ment 22 of the lock, as previously mentioned.

  The transistor Q5 controlling the conduction respectively the non-conduction of the transistor Q6 to ensure, from

  of a SCD inhibition circuit control signal

  pectively of the control signal of the inhibition circuit SCD *, at the transmission-reception switching time or

  turnaround close, blocking the entry of the re-

  reception of the transmission and reception module 12 of the res-

  pectively 22 of the lock is obtained when the part

  transmission of the transmission-reception module 12 of the res-

  pectively the emission part of the emission module-

  reception 22 of the lock are active in transmission.

  Description of an access control protocol

  between an electronic key 1 and an electronic lock

  2 constituting an access control device,

  form to the object of the present invention, will now be given in a preferred embodiment in conjunction

with Figures 6a and 6b.

  In general, we indicate that the key

  electronic 1 allows to generate and transmit

  unidirectional to electronic lock 2 if-

  general power such as the signal PS, a period of which is shown in the right part of FIG. 6a. This signal is constituted by an asymmetric periodic signal

as shown in Figure 5c.

  Following a first initialization step,

  sisting for example to initialize a counting variable r to the value 1, this counting variable representing for example the rank of successive periods of the signal of

  PS power consisting of a half period of high ampli-

  study and a half period of low amplitude, the proto-

  cole, object of the present invention, consists in transmitting in a step 1000, referenced a), from the electronic key 1 to the electronic lock 2, the power signal PS so as to provide over at least a half period of high amplitude to the electronic lock 2 the electrical energy conveyed by the power signal

  during this half period of high amplitude. We report

  excavator that of course the power transfer takes place

  kills in particular in the specific embodiment of Figure 5a at 80% during the 10% of the start time of

  the aforementioned half high amplitude period.

  Aforementioned step 1000 is associated with a step 1001 also bearing the reference b), for storing the electrical energy conveyed by the power signal.

  PS, this storage occurring at the level of the electric lock

  tronique 2. Of course, depending on the physical phenomenon

  that implemented to transfer and store the aforementioned electrical energy, it is indicated that in fact steps 1000 and 1001 of FIG. 6a can be concomitant, the transmission of electrical energy and the storage of this energy at the level of the lock, in particular via the input capacitors of the voltage regulator delivering the regulated voltage Vreg in the case of

  embodiment of Figure 5b are substantially con-

  comitants for the duration of the half high amplitude period considered. However, for the sake of clarity of the sequential diagram represented in FIG. 6a, steps a) and b), that is to say 1000 and 1001, are shown successively. The aforementioned steps are then followed during the next half low amplitude period of a bidirectional transfer of key and lock access control signals between the electronic key and lock. Of course, it is indicated that this bidirectional transfer of

  data is carried out according to an access control process

  non-limiting specific cès for which the bidirectional transfer 1002 of access control signals corresponds to

  all or part of the aforementioned access control process.

  In other words, step 1002, referenced c), can con-

  sister, either in a complete access control process between the electronic key and the electronic lock, or in a range of rank r of a control process

  full access. This process is thus distributed on several

  several successive slices of corresponding rank r and executed during half periods of low amplitude of the power signal PS. It will thus be understood that the access control protocol between an electronic key and an electronic lock, which is the subject of the present invention, can thus be implemented by means of a nested distribution of the process of transfer and storage of the electrical energy of the key and lock, followed by all or part of an actual access control process

  between the electronic key and lock.

  In the case where the bidirectional transfer of key and lock access control signals corresponds to part of the access control process, as mentioned previously, the access control protocol, in accordance with object of the present invention, further comprises steps consisting in memorizing at the level of the

  electronic key and lock the cal-

  intermediate asses corresponding to the part of the process

  access control, i.e. to the part implemented

  vre for the Tr tranche of key and lock access control signals. The step of memorizing the results

  of intermediate calculations is not shown in the figure

  gure 6a because it is a classic step in terms of

data processing.

  In the case cited above, steps a), b), c), that is to say 1000, 1001, 1002 shown in FIG. 6a, are then repeated over a succession of pairs of half periods of high amplitude and of low amplitude

  of the PS power signal to ensure in fact the complement

  study of the conduct of the access control protocol.

  In order to introduce a high level of security of the access control protocol, in accordance with the object of the present invention, it is indicated that the step of repeating steps a), b), c) previously mentioned, as well

  understood that the step of memorizing the intermediate calculations

  diaries, can then be made conditional on the satisfaction

  faction of a completeness test criterion from the part of the

access control process.

  In FIG. 6a, this step or this test criterion bears the reference 1003. On a negative response to the completeness test of the part of the access control process, the access control protocol, in accordance with the object of the present invention, is then terminated by an end step consisting of a refusal of access referenced

  1004. Indeed, it is thus possible to make the

  cess to the enclosure confined to the success of all successive sections of bidirectional transfer of signals from

  electronic key and lock access control.

  Thus, the aforementioned test 1003 can then be followed by a test 1005 relating to the completeness of the conduct of the access control protocol and the successful completion of the latter. The 1005 test is of course performed

  on positive response to the previous test 1003.

  On negative response to the above test 1005, the pro-

  complete access control has not been completed and a fortiori the access control protocol in accordance with

  the object of the present invention, a step 1006 is pre-

  view, which allows switching to the signal slice

  of access control of next row by the class operation-

  sique r = r + 1. Step 1006 allows the return to the previous step 1000, for the iterative conduct of the protocol

access control.

  On positive response to the above test 1005, the pro-

  access control tocol has been successfully completed and the latter introduces an end step 1007 into

which access is accepted.

  By way of nonlimiting example, it is indicated that the

  access control protocol, object of this invention

  tion, can be implemented for example in accordance with the access control process described in French patent application No. 98 01481, which is introduced in the present application for reference. We recall in

  particular, with reference to Figure 6b, that the pro-

  cessation of access control described in the patent application

  vet mentioned above consists, by way of nonlimiting example, in performing in a first tranche, denoted T1, a step of transmission by the electronic key, denoted lkj, of an identification request message, denoted Aki. This message

  of identification request is transmitted to lock no-

tee 2i.

  The aforementioned T1 tranche is followed by a T2 tranche

  consisting for example of the transmission of a message

  random riable, noted aij, by the electronic lock 2j

to the lkj electronic key.

  The aforementioned step T2 can then be followed by a

  slice T3, which consists, from data of

  initial validation Vj of the electronic key lkj, to be carried out

  kill a calculation of the signature of the random variable message, this signature being noted Ci = Sk's (aij), then

  of transmission of this signature Ci and of data from

  specific thesis DAj. This transmission is ef-

  carried out from the electronic key lkj towards the lock

electronic 2i.

  Slice T3 can then be followed by a tran-

  che T4, which is then performed at the service

  2i electronic rure from validation data

  initial Vi, this slice T4 then consisting of a

  rification of the authenticity of the signature value in

  specific authentication data function.

  With reference to the French patent application

  n 98 01481 previously cited in the description, we in-

  states that the steps of data transmission carried out at sections T1, T2, T3, T4 are for example carried out at

  during step 1002, referenced c in FIG. 6a, cha-

  that stage being of course carried out during the half

  riode of low amplitude of the power signal PS and having been preceded beforehand by a step of transfer of storage of energy corresponding to steps a) and b), that is to say 1000 and 1001 of the same figure 6a. It will be understood in particular that, depending on the calculation load to be carried out to conduct the calculation of the signature Ci, it is also possible to modulate the amount of energy

  transferred from the electronic key lkj to the electric lock

  tonic 2i as a function of this computational load required

* be able to implement each corresponding slice, and in particular the calculation time of the microprocessor, or microcontroller, equipping the logic calculation unit 21

  of the electronic lock. This modulation can be effective

  carried out in accordance with the protocol as defined above

  ment in the description in conjunction with Figures lb and

2b for example.

  With reference to the cited French patent application

  previously in the description, it is indicated that the tran-

  che T3 of calculation and transmission of the electronic key

  that lkj to the electronic lock 2i of the signature value Ci of the random variable message of authentication request and authentication data can be carried out for the calculation of the signature from

  a private signature key and this specific data

  DAj authentication ques, as described in the de-

  application for the aforementioned French patent.

  In the same way, the slice T4 of verification by the electronic lock 2i of the authenticity of the signature value as a function of the specific authentication data, can be implemented in accordance with

  to the lessons given in the French patent application

here above.

  It is indeed indicated that, for any electro-

  nique lkj, the references k and j correspond respectively-

  ment to an address or physical reference of the key and to

  a key validation address in accordance with the

  dications given in the French patent application pre-

  cited. Similarly, the index i of each electronic lock

  2i corresponds to a physical address assigned to the service

corresponding electronic rure.

  Finally, the signature calculation Ci and signature calculation verification operations are carried out by

  example using K'S private keys and public keys

  ques KP, K'P, under the conditions mentioned in the de-

  application for the aforementioned French patent.

  We have thus described an access control device.

  Ces between a key and an electronic lock implementing a particularly effective access control protocol insofar as complex operations of

  encryption - decryption of data can be combined

  quoted and made conditional on operations prior to

  energy transfer only allowing the authorization to conduct the calculation operations of

  aforementioned signature and verification.

  The access control device between an electronic key and lock and the access control protocol, objects of the present invention, appear to be particularly well suited to the management of a very large number of electronic locks from a in-

  seems reduced from electronic keys programmed for this purpose

  fet. They appear to be particularly well suited to the management of letter boxes, especially in rural areas, where letter boxes can be kept away from electrical power sources. In addition, depending on the complexity of the encryption - decryption algorithms selected, the access control device between an electronic key and lock and the access control protocol, objects of the present invention, can be implemented.

  is in use to ensure the management of controlled access loudspeakers

  served requiring high security control.

Claims (11)

  1. Access control device between a key   and an electronic lock, the electronic key comprises   both at least one source of electrical energy, a logical key calculation unit, a transceiver module   of key access control signals and the electric lock   tronic comprising at least one logical unit for calculating a lock and a module for transmitting and receiving lock access control signals for implementing an access control protocol between this electronic key and this lock, characterized in that said electronic key further comprises: - means generating a power signal, supplied by said source of electrical energy; and - key transfer means of said key and lock access control signals and of said power signal;   and in that said electronic lock comprises in- be:   - means for transferring said locks if-   key and lock access control signals and said power signal; and - means for storing the electrical energy conveyed by said power signal, which allows   ensure the unidirectional transfer of electrical energy   stick carried by said power signal from the electronic key to the electronic lock and the bidirectional transfer of the key access control signals and   lock between the electronic key and the electric lock tronic.   2. Device according to claim 1, character-   in that said key transfer means and   said lock transfer means consist of at least one primary winding and at least one secondary winding of a transformer respectively, said en-   primary and secondary bearings being coupled electroma-   genetically when placing the key   electronic and electronic lock.   3. Device according to one of claims 1 or   2, characterized in that, in the absence of an energy source   electric at the lock, unidirectional transfer   tional electrical energy conveyed by said signal   of power from the electronic key to the electric lock   is carried out prior to the two-way transfer   of the key access control signals and   lock between the electronic key and the electronic lock fuck.   4. Device according to one of claims 1 or   2, characterized in that, in the presence of a source of energy   auxiliary electric control at the lock, allows   both to ensure a standby function, the bidirectional transfer of key access control signals and   lock between the electronic key and the electric lock   is carried out prior to the unidirectional transfer   tional electrical energy conveyed by said signal   of power from the electronic key to the electric lock   tronic, said unidirectional transfer being carried out   conditionally to the success of said bidirectional transfer-   nel, constituting the access control protocol.   5. Device according to one of claims 1 or   2, characterized in that said power signal being constituted by an asymmetrical periodic signal, comprising a half period of high amplitude and a half period of low amplitude, the unidirectional transfer of   the electrical energy conveyed by said power signal   sance and the bidirectional transfer of the key and lock access control signals are performed alternately, over substantially a half period of high amplitude and substantially a half period of low amplitude amplitude respectively.   6. Electronic key comprising at least one source of electrical energy, a logical calculation unit   key, a module for transmitting and receiving signals   key access control for the implementation of an access control protocol between this electronic key and a   electronic lock based on access control signals   door lock generated by this electronic lock, characterized in that said electronic key further comprises: - means generating a power signal   powered by said source of electrical energy and pilo-   ted by said key calculating unit; and - key transfer means of said key and lock access control signals and of said signal   of power, said key transfer means comprise   as long as at least one winding mounted on a sleeve and inter-   connected to said means generating a signal   power and through said transmission module-   reception. 7. Electronic lock comprising at least one   logical unit for calculating a lock and an emission module   Zion-reception of lock access control signals for the implementation of an access control protocol between this electronic lock and an electronic key from key access control signals and a signal of power generated by this electronic key, characterized in that said electronic lock further comprises:   - means for transferring said locks if-   key and lock access control and said   power signal, said service transfer means   rure comprising at least one coil mounted on a cavity   cylindrical and interconnected to said emission module-   reception of lock access control signals; and - means for storing the electrical energy conveyed by said power signal, interconnected said winding.   8. Device according to one of claims 1 to   , characterized in that it includes an electric key   tronic according to claim 6 and an electro-lock   nique according to claim 7, the sleeve and the cavity   constituting the means for transferring the respective key   of the lock being made of a ma-   genetic. 9. Access control protocol between a key   electronic device according to claim 6 and an electric lock   tronic according to claim 7, the electronic key   allowing to generate and transmit in a unidi-   signal to the electronic lock a signal of   sance consisting of an asymmetrical periodic signal,   including a half period of low amplitude and a de-   mid period of high amplitude, characterized in that the-   said protocol consists at least of: a) transmitting from the electronic key to the lock   electronic said power signal so as to provide   to give, over a half period of high amplitude, to said electronic lock, the electric energy conveyed by said power signal during said half period; b) storing said electrical energy conveyed by said   power signal at said electric lock   tronic; and during the next half low amplitude period, c) performing a bidirectional transfer of signals from   access control between the key and the electronic lock   according to a specific access control process   that said bidirectional transfer of key and lock access control signals corresponding to   all or part of said access control process.   10. Access control protocol according to the res   dication 9, characterized in that when said bidirectional transfer of key access control signals and   of lock corresponds to a part of said process of con-   access control, said access control protocol   further carries the steps of:   d) memorize at the level of the electric key and lock   tronic the results of intermediate computations cor-   responding to said part of said access control process; e) repeating steps a), b), c) and d) over a succession of pairs of half periods of high amplitude and low amplitude of said power signal to ensure the complete conduct of said access control protocol.   11. Access control protocol according to the res   dication 10, characterized in that step e) consisting in repeating steps a), b), c) and d) is conditional on   a completeness test criterion for said part of the program cessation of access control.