IT202000007078A1 - Electronic system to control the opening of an opto-electronic lock of an access door, relative opto-electronic lock and opto-electronic key for opening the lock. - Google Patents

Description

DESCRIPTION

Attached to a patent application for INDUSTRIAL INVENTION having the title

? Electronic system for controlling the opening of an opto-electronic lock of an access door, relative opto-electronic lock and opto-electronic key for opening the lock?

Technical field of the invention

The present invention generally relates to the electronics sector.

Pi? in particular, the present invention? relating to an electronic system to control the opening of an electronic lock mounted for example on a vehicle door or on an access door to a home.

Known technique

AND? I notice the use of locks mounted on a motor vehicle door, in order to allow the vehicle door to be locked in the closed position.

Mechanical type locks are known which use a mechanical key inserted in the lock itself, in which the key locks the lock in the closed position by means of a rotation of the key itself.

Electronic locks and keys are also known, in which the electronic key commands the opening and closing of a motorized electronic lock by means of the radio transmission of an authorization key between the key and the lock, for example using RFID technology. NFC or Bluetooth.

The mechanical type locks can be forced to open using appropriate mechanical break-in tools, and moreover the same mechanical key can? be easily copied.

Even an electronic key can? be deceived, in what? possible to intercept the authorization key transmitted via radio and? sensitive to various cyber attack methods.

Brief summary of the invention

The present invention relates to an electronic system for controlling the opening of an opto-electronic lock of a door giving access to a limited environment, in which the system? defined in the attached claim 1 and by its preferred embodiments described in the dependent claims 2 to 6.

The Applicant has perceived that the electronic system in accordance with the present invention has the following advantages:

- improves the security of communication between the optoelectronic key and the associated lock;

-? insensitive to radio frequency interference signals;

- allows you to define permissions with which a particular user can? interact with a specific lock, in terms of time (for example, only at certain times or up to a specific date) and / or in terms of the number of accesses allowed.

The present invention also relates to a method for controlling the opening of an opto-electronic lock of an access door as defined in the attached claim 7 and in the preferred embodiments described in dependent claims 8 to 11.

The present invention also relates to a non-transient storage medium as defined in the attached claim 12.

The present invention also relates to a motor vehicle as defined in the attached claim 13.

The present invention also relates to an optoelectronic key for controlling the opening of a lock as defined in the attached claim 14.

The present invention also relates to an optoelectronic lock for controlling the opening of an access door to a limited environment as defined in the attached claim 15.

The present invention also relates to a network server for controlling the opening of a lock of an access door in a limited environment as defined in the attached claim 16.

Brief description of the drawings

Further characteristics and advantages of the invention will emerge from the following description of a preferred embodiment and its variants, provided by way of example with reference to the attached drawings, in which:

Figure 1 shows a block diagram of an electronic system for controlling an electronic lock of a vehicle according to the invention;

Figure 2 above shows a schematic of the method of generating a time-based once valid keyword used in the electronic system of the invention;

Figure 2 below shows a data packet transmitted by an opto-electronic key of the electronic system of the invention;

Figures 3A-3B show a configuration step of the electronic system according to a first embodiment of the invention; Figure 3C shows a phase of normal operation of the electronic system according to the first embodiment of the invention; Figures 4A-4B show a configuration step of the electronic system according to a second embodiment of the invention;

Figure 4C shows a phase of normal operation of the electronic system according to the second embodiment of the invention.

Detailed description of the invention

It should be noted that in the following description identical or similar blocks, components or modules are indicated in the figures with the same numerical references, even if they are shown in different embodiments of the invention.

With reference to Figure 1, an electronic system 10 is shown for controlling a lock 3 of a motor vehicle 50, such as for example a thermal engine, electric or hybrid thermal / electric vehicle.

The electronic system 10 comprises the opto-electronic lock 3, an opto-electronic key 2 and a network server 4.

Preferably, the electronic system 10 further comprises an electronic device 5 which is used to configure the electronic system 10, as will happen? explained more? in detail below.

The electronic system 10? configured to work in two ways? of operation:

- a mode? online (online), where? a long-distance data link is available between the opto-electronic lock 3 of the motor vehicle 50 and the network server 4;

- a mode? offline (offline), where not? the long-distance data connection is available between the opto-electronic lock 3 of the motor vehicle 50 and the network server 4.

In addition, each of the two modes? of operation comprises a step of configuring the electronic system 10 and a step of normal operation.

The opto-electronic key 2 belongs to a subject 6 (ie a user) who? the owner of the vehicle 50.

The opto-electronic key 2 comprises a non-volatile memory 2-1 which stores the following configuration parameters:

- Identification-Key;

- User-ID.

L? Identification-Key (hereinafter abbreviated with KEY_ID)? a unique identifier associated with the opto-electronic key 2 (for example, an alphanumeric string), which is assigned by the manufacturer of the vehicle 50 and is stored in the memory 2-1 inside the electronic key 2; therefore the vehicle manufacturer has a database that contains unique KEY_ID values, ie the vehicle manufacturer assigns a different KEY_ID to opto-electronic keys that belong to different vehicles.

Alternatively, the KEY_ID? a unique identifier associated with key 2 that is assigned by the producer of the key 2 itself, therefore the producer of keys (similar to the opto-electronic key 2) has a database that contains unique KEY_ID values, i.e. the producer of the keys assigns a KEY_ID different to optoelectronic keys belonging to different vehicles.

The User-Identifier (abbreviated hereinafter as USER_ID)? a code that is generated as a function of data representative of an identity? digital image of the subject 6.

The identity digital can? be one of the following:

- a biometric profile of the subject 6, such as for example a fingerprint of a finger of the hand of the subject 6, data representative of the face of the subject 6, the voice timbre of the subject 6;

- credentials associated with subject 6, consisting of a username and a keyword;

- an authentication token provided by an external authentication service, such as a Google, Microsoft or Facebook account.

Memory 2-1? then configured to store further identification data of an identity? digital reference of subject 6, which have been acquired by subject 6 in safe conditions during a configuration phase which? previous to the phase of normal operation of the system 10, how will it come? explained more? in detail below.

Observe that? can you associate with the same subject 6 pi? of a User-Identifier, such as for example a first User-Identifier generated according to a biometric parameter of the subject 6 and a second User-Identifier generated according to a Google account of the subject 6.

For the purposes of the explanation of the invention, it is considered later that the data representative of the identity? of subject 6 are a biometric parameter of subject 6, in particular a fingerprint of a finger of subject 6 (for example, thumb or index finger), therefore the? User-ID? a code generated as a function of the fingerprint of a finger of the subject 6: in this case the opto-electronic key 2 comprises a fingerprint sensor configured to acquire in real time a fingerprint of a finger of the subject 6 (for example, thumb or forefinger).

Advantageously, during the configuration phase, a further configuration parameter indicated with Symmetric Key, hereinafter abbreviated as S-KEY, is associated with the opto-electronic key 2.

The Symmetric Key? a secret key shared between the opto-electronic key 2 and the opto-electronic lock 3; in other words, the Symmetric Key? been exchanged in advance during the configuration phase (prior to the first operation of the normal operation phase) by means of a safe channel, how will it be? explained more? in detail below in relation to the description of Figures 3A and 4A.

The Symmetric Key? a value composed of at least 40 bits, preferably equal to 128 bits, such as for example a set of randomly generated bytes, a passphrase or a long string of alphanumeric characters.

Is the value of the Symmetric Key provided for example by an Authority? of Authorized Certification: therefore the manufacturer of the vehicle 50 obtains a value of the Symmetric Key from an Authority? of Certification, then the manufacturer of the vehicle 50 configures the electronic key 2 so as to memorize in the memory 2-1 the value of the S-KEY Symmetric Key, together with the value of the Key Identification KEY_ID, thus memorizing? a pair (KEY_ID, S-KEY).

The Symmetric Key? a code that is used to encrypt a data packet transmitted by the opto-electronic key 2 to the opto-electronic lock 3 by means of a symmetrical type of encryption, how will it happen? explained more? in detail below.

The opto-electronic key 2 includes a unit? processing (for example, a microcontroller) and memory 2-1.

The opto-electronic key 2 also comprises an optical source (i.e. an optical transmitter) to generate an optical beam F_O which is transmitted towards the opto-electronic lock 3, typically in the visible light band, for example with a frequency between 380 and 780 nanometers.

Figure 2 shows in the lower part a data packet 30 which is transported by the optical beam F_O generated by the optical source of the opto-electronic key 2.

The data packet 30 comprises a first field 30-1 which contains the Identification-Key and comprises a second field (indicated with 30-2 and 30-3) which contains the Payload.

The Payload in turn includes a 30-2 field which includes the User-ID and a further 30-3 field which includes a keyword (or token) valid only once based on time and valid for a limited time interval. , which is indicated with TOTP (Time-based One-Time Password) in the RFC6238 standard issued by the IETF standardization body.

The time-based once-valid keyword? a variable code that is generated in the opto-electronic key 2 as a function of a current time and as a function of a value indicated with Shared Secret, using an algorithm defined in the RFC6238 standard.

Specifically, TOTP? a password (ie a token) that? valid only once and for a certain time interval, for example equal to 30 seconds or 60 seconds.

Shared Secret? a code having a length of at least 128 bits which is generated as a function of the User-ID (USER_ID) and (in the case of use of symmetric cryptography) also as a function of the Symmetric Key (S-KEY).

Specifically, Shared Secret? generated by means of a hash function that receives in input the value of USER_ID or (in the case of use of symmetric cryptography) a combination of the values of USER_ID and S KEY, then said hash function generates a binary string of fixed length ( for example equal to 128 bits), using a mathematical algorithm that maps data of arbitrary length into a binary string of fixed length.

An example of a hash function? the family of SHA (Secure Hash Algorithm) functions which includes the following:

- SHA-0: outputs a string composed of 160 bits;

- SHA-1: outputs a string composed of 160 bits;

- SHA-2: outputs a string composed of 224, 256, 384 or 512 bits;

- SHA-3: outputs a string composed of 224, 256, 384 or 512 bits.

Figure 2 shows in the upper part a diagram of the method of generating the TOTP value carried out by means of an appropriate software program executed on the unit? processing of the optoelectronic key 2 during the phase of normal operation of the electronic system 10, in the mode? online or offline.

The unit? processing of the opto-electronic key 2 receives in input the pair of the Identification-Key (ID_KEY) -Symmetrical Key (S-KEY) parameters, which have been previously stored in the local memory 2-1 of the opto-electronic key 2; also the unit? processing receives in input the value of the User-Identifier which? been generated in function of an identity? fingerprint of subject 6, such as a biometric parameter of subject 6, in particular the fingerprint of one of his fingers.

Subsequently, the unit? optoelectronic key processing 2 calculates the Shared Secret value as a function of the values of the User-ID and the Symmetric Key, using a hash function that receives in input a combination of the values of the User-Identifier and the Symmetric Key.

Subsequently, the unit? optoelectronic key 2 processing generates the TOTP value as a function of the Shared Secret value and a time stamp value using the algorithm defined in the RFC6238 standard to which reference should be made for more details, in which the time stamp ? derived from a reference time and a time step.

Subsequently, the unit? processing of the optoelectronic key 2 performs an encryption of the set of the value of the User-Identifier and of the TOTP value using the value of the Symmetric Key, thus generating a Paying Load that includes an encrypted value of the set of the User-Identifier and by TOTP.

Finally, the unit? processing of the opto-electronic key 2 generates the data packet 30 having the first field 30-1 which contains the Key-Identifier and a second field 30-2, 30-3 which contains the Paying Load, which in turn contains the ? User-ID and TOTP in encrypted form.

The opto-electronic lock 3? positioned inside the passenger compartment of the motor vehicle 50, so that this is visible by means of an optical path towards the outside of the vehicle 50, through a surface 20 of the vehicle 50 which is transparent with respect to the optical beam F_O, such as for example a glass of a vehicle window or windscreen 50.

For example, the opto-electronic lock 3? mounted inside the passenger compartment of the vehicle 50 in the vicinity? of the windshield 20 (ie the front glass) of the vehicle 50, in particular in the vicinity? a central position of the upper edge of the windscreen 20.

Alternatively,? It is possible to use an optical fiber inserted along a through hole that passes through the vehicle door 50: in this way the optical fiber? such as to receive in input the optical beam F_O generated by the key 2,? such as to guide the optical beam received from the entrance face (positioned at one end of the hole outside the door) to an exit face (positioned at another end of the hole inside the door), therefore the optical fiber? such as to generate at its output an optical beam which is received by the optical sensor of the lock 3 inside the vehicle 50.

Note that the invention is not? limited to a lock for opening a motor vehicle door, but it can? be used more? in general for controlling the opening of an access door to a limited environment, such as the access door to a house or an industrial environment, provided that it is possible to identify (through the access door) a optical path between the key 2 placed outside the limited room and the lock 3 located inside said limited room; in this case the KEY_ID? a unique identifier associated with key 2 which is assigned by the manufacturer of the key 2 itself, therefore the manufacturer of the opto-electronic keys has a database that contains unique KEY_ID values, i.e. the manufacturer assigns a different KEY_ID to opto-electronic keys that belong to different access doors of homes or industrial environments.

The opto-electronic lock 3 includes a unit? processing (for example, a microcontroller or a microprocessor) and an optical receiver to receive an optical beam F_O transmitted by the opto-electronic key 2.

The optical receiver? for example a photo-diode.

The opto-electronic lock 3 further comprises a long-distance wireless signal transceiver configured to transmit towards the server device 4, during a phase of normal operation of the mode. online, a long distance wireless signal S2_r_ld carrying a message containing the Key-Identification (KEY_ID), the User-Identification (USER_ID) and TOTP, how will it happen? explained more? in detail below in relation to the description of Figure 3C.

Furthermore, during the phase of normal operation of the mode? online, the lock 3 transceiver? configured to receive from the network server 4 the wireless long-distance signal S2_ld which carries a message indicative of an authorization granted to the opening / closing of lock 3 or indicative of an authorization denied to the opening / closing of lock 3.

In case of operation of the system 10 in the mode? offline, the opto-electronic lock 3 comprises a memory 3-1 of the non-volatile type which? connected directly or indirectly with the lock 3, in which said memory 3-1? configured to store the Identification-Key (KEY_ID)-Symmetric Key (S-KEY) pair and the Identification-User pair (USER_ID) - Shared Secret.

During the phase of normal operation of the system in the mode? offline, the unit? of processing of the optoelectronic lock 3? configured to locally generate a TOTP, depending on the Shared Secret value and the value of a time stamp, for example as defined in the RFC6238 standard, where the time stamp? for example derived from a reference time and a time step.

Furthermore, during the phase of normal operation of the system 10 in the mode? offline, the unit? of processing of the optoelectronic lock 3? configured to compare the locally generated TOTP value with the transmitted TOTP value (i.e. the one transmitted by the opto-electronic key 2 by means of the optical beam F_O):

- if the local TOTP value is equal to the transmitted TOTP value, the unit? of processing of the opto-electronic lock 3? configured to generate a command signal for closing the lock 3 if it is in an open position or, vice versa, an opening command for the lock 3 if it is in a closed position;

- if the local TOTP value is different from the transmitted TOTP value, the unit? of processing of the opto-electronic lock 3? configured to generate an alarm signal representative of an attempted opening / closing of the lock 3 by a user with an unauthorized key 2.

The alarm signal? configurable and can? be for example:

- a loud sound signal? medium-strong emitted from a vehicle loudspeaker 50;

- a low intensity sound signal? emitted by a miniaturized loudspeaker integrated in key 2;

- a visual signal emitted by the optical source of the key 2, such as a steady or flashing red light for a short period of time (for example, a few seconds).

Preferably, if the local TOTP value is different from the transmitted TOTP value, the unit? processing of lock 3? configured to generate (in addition to the alarm signal indicated above) the command signal for the closing of lock 3 (i.e. locking the opening of lock 3), both in the case in which the lock 3 is in the open position, and in the case of in which the lock 3 is already? in the closed position, in order to block access to the interior of the vehicle 50 for a user having an unauthorized key 2.

For example, the lock 3 comprises an electric motor and suitable mechanical means (for example, a sliding piston) for locking / unlocking the opening of the vehicle door 50, in which said mechanical means are operated by the electric motor as a function of a signal. piloting which depends on the value of the command signal generated by the unit? lock processing 3.

Advantageously, symmetric cryptography is used with a secret key shared between the electronic key 2 and the network server 4 (online mode) or between the electronic key 2 and the optoelectronic lock 3 (offline mode), in order to protect the messages exchanged between the electronic device 5 and the network server 4.

In this case the memory 2-1 of the key 2 and the memory 4-1 of the network server 4 are configured to further store the value of the Symmetric Key (S-KEY) associated with the Identification-Key (ID_KEY), that is a pair of values (KEY_ID, S-KEY): this is obtained by means of the first part of the configuration phase of the mode? online and offline, how will it come? explained more? in detail below in relation to the description of Figures 3A and 4A.

During the phase of normal operation of the mode? online and offline, the unit? opto-electronic key 2 has the function of generating the time-based keyword valid once (TOTP) for a defined time interval.

A value of TOTP is generated in the opto-electronic key 2 as illustrated above with reference to the description of Figure 2 and another value of TOTP is generated in the network server 4 (online mode) or in the lock 3 (mode not in line) during the normal operation of the electronic system 10, how will it be? explained more? in detail below in Figures 3C and 4C relating to the description of the normal operation of the system 10.

The unit? processing key 2? moreover configured, during the phase of normal operation, to read from the memory 2-1 data identifying the identity? digital reference (which was previously configured in the second part of the configuration phase) of subject 6 (for example, the fingerprint of one of his fingers), then the unit? processing key 2? configured to compare the identity? digital sample of subject 6 with respect to the identity? digital reference of subject 6:

- in the event that the value of the identity? digital sample is the same as that of the identity? digital reference, the unit? processing? configured to continue with the generation of TOTP and subsequent transmission of the optical beam F_O which carries the data packet 30;

- in the event that the value of the identity? digital sample is different from that of the identity? digital reference, the unit? processing? configured to ignore the identity? digital sample acquired, inhibiting cos? the transmission of the data packet 30 towards the lock 3, therefore the unit? processing of key 2 is waiting to receive a new identity value? digital sample.

It should be noted that the negative confrontation of identity? digital can? be caused both by an attempt to open (or close) the door of the vehicle 50 using a key 2 not authorized for said vehicle 50, and in the event that incorrect identity data has been acquired? fingerprint sample of an authorized subject 6 (for example, a fingerprint of a wet or dirty fingertip of the authorized subject 6).

Advantageously, in the event that the unit? processing of the key 2 is such as to detect a plurality of of attempts to open / close the lock 3 with negative comparison of the identity? digital in a limited time interval (for example, at least three failed attempts within a time interval equal to 10 seconds), the unit? processing key 2? configured to generate an alarm signal representative of an attempted opening / closing of the lock 3 by a user having an identity? unauthorized digital for that key 2 (for example, key 2 was stolen from the authorized user).

The alarm signal? configurable and can? be for example:

- a loud sound signal? medium-strong emitted from a vehicle loudspeaker 50;

- a low intensity sound signal? emitted by a miniaturized loudspeaker integrated in key 2;

- a visual signal emitted by the optical source of the key 2, such as a steady or flashing red light for a short period of time (for example, a few seconds).

The electronic key 2 also comprises suitable electronic components for driving the optical source and a battery for powering the optical source and the electronic components.

Advantageously, the optical source of the opto-electronic key 2? a light emitting diode (LED).

The electronic device 5 comprises a unit? signal transceiver (for example, a wireless signal of the Bluetooth or Wifi type) and a transceiver of medium-long distance signals (for example, a wireless signal of the type 2G, 3G, 4G or 5G).

The electronic device 5 can? be of the fixed type (for example, a fixed personal computer) equipped with suitable wired data communication interfaces, for example of the Ethernet and USB type.

Alternatively, the electronic device 5? of the mobile type (such as a smartphone, a tablet or a portable personal computer) and includes a short-distance wireless signal transceiver (for example Bluetooth or Wifi) to exchange a short-distance wireless signal S_r_sd with the key 2 and a medium-long distance wireless signal transceiver (for example 2G, 3G, 4G or 5G type) to transmit a long distance wireless signal S1_r_ld towards the network device 4.

The unit processing of the electronic device 5 runs a software program (or a software application) to configure the electronic system 10 during the configuration phase of the mode? online and offline.

In particular, during a first part of the configuration phase of the mode? online and offline, the electronic device short distance signal transceiver 5? configured to transmit to the opto-electronic key 2 the short-distance wireless signal S_r_sd which carries a key registration request and? configured to receive the short-distance wireless signal S_r_sd which carries the ID-Key (ID-KEY) and (in the case of using symmetric encryption) also the Secret Key (KEY-S).

Advantageously, the short-distance wireless signal S_r_sd is transmitted over a secure channel that uses encryption, in particular the TLS (Transport Layer Security) protocol version 1.2 or higher.

Furthermore, during a second part of the configuration phase of the mode? online and offline, the electronic device short distance signal transceiver 5? configured to transmit to the opto-electronic key 2 the short-distance wireless signal S_r_sd which carries a request for registration of a user ID and? configured to receive from key 2 the short-distance wireless signal S_r_sd which carries the User-ID (USER_ID), Secret Key and the Key-ID (KEY_ID) associated with them.

Furthermore, during the second part of the configuration phase of the mode? online, the medium-long distance signal transceiver S1_r_ld of the electronic device 5? configured to transmit to the network server 4 the long distance wireless signal S1_r_ld which carries KEY_ID, USER_ID and Shared Secret.

Advantageously, the medium-long distance signal S1_r_ld is transmitted over a secure channel that uses encryption, in particular the TLS (Transport Layer Security) protocol version 1.2 or higher.

Network server 4? an electronic device positioned within a medium-long distance telecommunications network 15 (for example, the Internet network).

Network server 4 runs cloud-like services using for example Web Services.

The network server 4 comprises a medium-long distance signal transceiver and a unit? processing (for example, a microprocessor).

The network server 4 comprises a non-volatile memory 4-1 configured to store, in case of operation of the system 10 in the mode? online, the value of Key-Identifier (KEY_ID) and the User-Identifier (USER_ID) -Shared Secret value pair.

Furthermore, in the case of use of symmetric cryptography between the key 2 and the server 4, the memory 4-1? further configured to store the value of the Symmetric Key (KEY-S) associated with the Identification-Key (ID_KEY), that is the pair of values (ID_KEY-KEY-S).

During the phase of normal operation of the system 10 in the mode? online, the network server transceiver 4? configured to receive a medium-long distance signal S2_ld carrying a message containing the Key-Identification (KEY_ID), the User-Identification (USER_ID) and TOTP transmitted, then the transceiver? configured to extract at least the value of KEY_ID from the received message.

During the phase of normal operation of the system in the mode? online, the unit? network server processing 4? configured to receive the data packet 30 carrying the KEY_ID and the Paying Load,? configured to extract the value of USER_ID and TOTP from the Payload,? configured to read from memory 4-1 the pair of values (USER_ID, Shared Secret) corresponding to the value of USER_ID extracted and finally? configured to identify the Shared Secret value associated with the extracted USER_ID value.

In the event that the Paying Load is encrypted with a symmetric cryptography, the unit? processing? further configured to extract the value of KEY_ID from data packet 30,? configured to read from memory 4-1 the pair of values (KEY_ID, S-KEY) corresponding to the received KEY_ID value and identify the S-KEY value associated with the extracted value of KEY_ID, therefore the unit? network server processing 4? configured to perform the decryption from the Paying Load (using the identified value of KEY-S) and finally extracting the USER_ID and TOTP values from the Paying Load.

Furthermore, during the phase of normal operation of the system in the mode? online, the unit? network server processing 4? configured to locally generate a TOTP, according to the Shared Secret value read from memory 4-1 and the value of a time stamp (for example derived from a reference time and a time step) as defined in the RFC6238 standard.

Furthermore, during the phase of normal operation of the system 10 in the mode? online, the unit? network server processing 4? configured to compare the TOTP value generated locally in the network server 4 with the transmitted TOTP value (i.e. the one transmitted by the opto-electronic lock 3 and then received by means of the medium-long distance signal S2_ld):

- if the local TOTP value is equal to the transmitted TOTP value, the network server transceiver 4? configured to transmit to lock 3 the medium-long distance signal S2_ld which carries a message indicating an authorization granted to the opening of lock 3 in the case in which this is in a closed position or an authorization granted to close the lock 3 in the case in which this is in an open position;

- if the local TOTP value is different from the transmitted TOTP value, the network server transceiver 4? configured to transmit to lock 3 the medium-long distance signal S2_ld which carries a message indicating an authorization denied to unlock the opening of lock 3 in the event that it is in a closed position or an authorization denied to block the closing of the lock 3 if this is in an open position.

Sar? now described the operation of the electronic system 10 in the mode? on-line operation, also referring to Figures 1, 2A, 2B and 2C.

For the purposes of the explanation of the invention, the following hypotheses are considered:

- the opto-electronic key 2 comprises a fingerprint sensor and an LED for generating the optical beam F_O;

- the memory 2-1 inside the opto-electronic key 2 stores a pair of Key Identification values (KEY_ID) - Symmetric Key (S-KEY), a pair of values (USER_ID-Shared Secret) and identification data of the thumb reference of subject 6, where USER_ID? associated with subject 6 and KEY_ID? associated with key 2 belonging to subject 6;

- memory 4-1 of the network server stores a pair of values (KEY_ID-KEY-S) and a pair of values (USER_ID, Shared Secret), in which USER_ID? associated with subject 6 and KEY_ID? associated with key 2 belonging to subject 6;

- the opto-electronic lock 3 comprises a photo-diode for detecting the optical beam F_O;

- the electronic device 5? a smartphone;

- the long distance signal S1_r_ld? a wireless signal of the mobile radio type (for example, 4G or 5G);

- the short distance signal S_r_sd? a wireless signal of the Wi-Fi type;

- a shared symmetric cryptography is used to protect the data that are transmitted by means of the communication channel between the key 2, the lock 3 and the network server 4;

- TOTP is generated as defined in the RFC6238 and Shared Secret standard with a hash function that receives in input a combination of the USER_ID and S-KEY values.

Is it possible to observe that? present a configuration step comprising a first part having a duration? T1 (Figure 2A) and a second part having a second duration? T2 (Figure 2B); furthermore ? there is a subsequent phase of normal operation having a duration? T3-1 (Figure 2C).

The configuration phase? between the instant t1 and the instant t19. At the initial instant t1 the first part of the configuration phase begins: the subject 6 starts an appropriate application on the smartphone 5 and generates, by means of it, a request for registration of the opto-electronic key 2.

The smartphone 5 then transmits to the opto-electronic key 2 the short-distance wireless signal S_r_sd which carries said registration request.

At instant t2 (subsequent to t1) the transceiver of the optoelectronic key 2 receives the short-distance wireless signal S_r_sd which carries said registration request, therefore at instant t3 (subsequent to t2) the unit? processing function of the opto-electronic key 2 reads the pair of values (KEY-ID, S-KEY) from the memory 2-1 of the opto-electronic key 2.

At instant t4 (following t3) the transceiver of the optoelectronic key 2 transmits the short-distance wireless signal S_r_sd to the smartphone 5, which carries a message that carries the pair of values (ID-KEY, KEY-S).

At instant t5 (following t4) the short-distance transceiver of the smartphone 5 receives the short-distance wireless signal S_r_sd which carries said message that carries the pair of values (ID-KEY, KEY-S), then instantly t6 (subsequent to t5) the long-distance transceiver of the smartphone 5 transmits to the network server 4 the long-distance wireless signal S1_r_ld which carries a message that contains a configuration request and contains the pair of values (ID-KEY, KEY-S).

At instant t7 (following t6) the transceiver of the network server 4 receives the long-distance wireless signal S1_r_ld which carries said message which contains the configuration request and the pair of values (ID-KEY, KEY-S), then at the instant t8 the unit? the network server 4 stores the pair of values (KEY-ID, S-KEY) in the memory 4-1 of the network server 4 and then ends the first part of the configuration phase.

Therefore, at the end of the first part of the configuration phase of the mode? online the pair of values (ID-KEY, KEY-S)? been memorized in the memory 4-1 of the network server 4, in which said pair of memorized values (ID-KEY, KEY-S) will come? subsequently used by the unit? processing of the network server 4 in the phase of normal operation of the system 10 in the mode? on line.

The first part of the configuration phase is carried out for example by the manufacturer of the vehicle 50 during the production of the vehicle 50 or at the end of the production of the vehicle 50 itself, in any case before the sale of the vehicle 50. in general, the car manufacturer that produces the vehicle 50 issues a batch of opto-electronic keys (made as key 2) and then configures unique values of pairs (ID-KEY, KEY-S) in different keys of the lot of keys and it configures in the memory 41 of the network server 4 the pairs of values (ID-KEY, KEY-S) of all the keys of the pool.

At the initial instant t10 the second part of the configuration phase begins, in which the configuration of the fingerprint of the subject 6 is carried out.

The subject 6 therefore generates, by means of the application running on the smartphone 5, a request for registration of a user identifier.

The smartphone 5 then transmits to the opto-electronic key 2 the short-distance wireless signal S_r_sd which carries said request for registration of the user identification.

At instant t11 (following t10) the transceiver of the opto-electronic key 2 receives the short-distance wireless signal S_r_sd which carries the request for registration of the user ID, therefore the opto-electronic key 2 remains waiting to acquire a fingerprint of a finger (for example, the thumb) of the subject 6, by means of the integrated sensor.

At instant t12 (following t11) the subject 6 places the tip of his finger (thumb) on the sensor of the opto-electronic key 2, then the opto-electronic key 2 acquires the reference fingerprint of the fingertip (thumb ) of subject 6, which therefore constitutes its identity? digital reference.

At the instant t13 (following t12) the unit? processing of the opto-electronic key 2 generates a value of a User-Identifier (USER_ID) according to the data representative of the reference fingerprint (acquired at instant t12) of the fingertip of the finger (thumb) of the subject 6.

Furthermore, at the instant t13 the unit? processing of the optoelectronic key 2 generates a value of the Shared Secret as a function of the value of USER_ID and the value of S KEY, using a hash function for example at 128 which receives in input a combination of the values of USER_ID and S KEY, generating then a 128-bit string that constitutes cos? the value of Shared Secret.

At the instant t14 (following t13) the unit? opto-electronic key 2 processing stores the pair of values (USER_ID-Shared Secret) in the memory 2-1 of the optoelectronic key 2.

At the instant t15 (following t14) the unit? processing of the opto-electronic key 2 reads the value of KEY_ID from memory 2-1, then the transceiver of the opto-electronic key 2 transmits to the smartphone 5 the short-distance wireless signal S_r_sd which carries the value of the KEY_ID and the pair of values (USER_ID -Shared Secret) that were generated in the opto-electronic key 2 at time t13.

At instant t16 (subsequent to t15) the short-distance signal transceiver of the smartphone 5 receives the short-distance wireless signal S_r_sd which carries the KEY_ID value and the pair of values (USER_ID -Shared Secret).

At instant t17 (subsequent to t16) the medium-long distance signal transceiver of the smartphone 5 transmits the long-distance wireless signal S1_r_ld to the network server 5 which carries the value of KEY_ID and the pair of values (USER_ID - Shared Secret).

At instant t18 (following t17) the transceiver of network server 4 receives the long-distance wireless signal S1_r_ld which carries the value of KEY_ID and the pair of values (USER_ID d- Shared Secret), then at instant t19 l 'unit? processing of the network server 4 stores the pair of values (USER_ID -Shared Secret) in the memory 4-1 of the network server 4 and ends the second part of the configuration phase (and therefore also the entire configuration phase) .

Therefore, at the end of the configuration phase of the mode? online, the pair of values (ID-KEY, KEY-S) and the pair of values (ID_USER, Shared Secret) have been stored in the memory 4-1 of the network server 4, in which said values stored in the pair (IDKEY, KEY-S) and the pair (USER_ID-Shared Secret) will be used subsequently by the unit? processing of the network server 4 in the phase of normal operation of the system 10 in the mode? on line.

The second part of the configuration phase is carried out, for example, immediately after the sale of the vehicle 50.

In the event that the car manufacturer has issued a batch of keys, only key 2 of the vehicle 50 is recorded in the second part of the configuration phase. actually been sold.

At the instant t21 begins the phase of normal operation of the mode? online system 10.

At instant t21 the subject 6 places the tip of a finger (thumb) on the sensor of the optoelectronic key 2, then the optoelectronic key 2 acquires the fingerprint of the fingertip of the finger (thumb) of the subject 6, which therefore constitutes the its identity? digital sample acquired in real time.

At time t22 (following t21) the unit? processing of the opto-electronic key 2 generates a value of USER_ID according to the representative data of the sample fingerprint (acquired at instant t21) of the fingertip of the finger (thumb) of the subject 6, therefore the unit? processing reads from memory 2-1 the pair of values (USER_ID, Shared Secret) corresponding to the received USER_ID value and then identifies the Shared Secret value associated with the generated USER_ID value.

Subsequently, the unit? processing of the optoelectronic key 2 makes a comparison between the value of the sample fingerprint (generated in real time) and the value of the reference fingerprint (previously stored in memory 2-1 in the second part of the configuration phase) and detects that the two values are equal.

At the instant t23 (following t22) the unit? processing of the opto-electronic key 2 generates in real time a value of a TOTP, as a function of the identified Shared Secret value and the value of a time stamp derived from a reference time and a time step as defined in RFC6238 standard, using for said generation the algorithm defined in the same RFC6238 standard: said generated value of TOTP to key 2 will come? indicated later with TOTP transmitted, to distinguish it from another TOTP that will come? locally generated to the network server 4.

At instant t24 (subsequent to t23) subject 6 presses a button on the opto-electronic key 2, then the unit? key 2 processing reads from memory 2-1 the pair of values (KEY_ID, S-KEY) (previously stored in memory 2-1 in the configuration phase) and the corresponding value of USER_ID (previously stored in memory 2-1) , then the unit? processing of key 2 reads the value of KEY-S from memory 2-1 and encrypts the Payload having field 30-2 which contains the value of USER_ID and field 30-3 which contains the value of TOTP transmitted ( generated previously at time t23), generating cos? the encrypted Payload.

Subsequently, the LED of the opto-electronic key 2 generates the optical beam F_O which carries the data packet 30 having the first field 30-1 which contains the clear value of ID_KEY and having a second field which includes the encrypted Payload.

The optical beam F_O passes through the glass of the windscreen of the vehicle 50 (or the glass of a window of a vehicle door 50) and at the instant t25 it is received by the photo-diode of the opto-electronic lock 3 inside the vehicle 50.

At instant t26 the long-distance signal transceiver of the opto-electronic lock 3 transmits to the network server 4 the long-distance signal S2_ld which carries the data packet 30 which contains the unencrypted value of the key-identifier (KEY_ID) and the encrypted value of the USER_ID and the transmitted TOTP contained in the Payload field.

At instant t27 the long-distance signal transceiver of the network server 4 receives the long-distance signal S2_ld which carries a message containing the clear value of the KEY_ID and the encrypted value of the Payload (which in turn contains USER_ID and TOTP transmitted) and forwards said KEY_ID and Payload values to the unit? network server processing 4.

At instant t28 the unit? processing of the network server 4 receives the data packet 30 which carries the KEY_ID value (in clear text) and the Payload (encrypted) and extracts the KEY_ID value from the message the KEY_ID value; subsequently, the unit? processing reads from memory 4-1 the pair of values (KEY_ID, S-KEY) corresponding to the extracted value of KEY_ID and then identifies the value of S-KEY associated with the received value of KEY_ID.

Subsequently the unit? network server 4 decrypts the Payload using the identified S-KEY value, then extracts the USER_ID and TOTP values transmitted from the Paying load.

Subsequently the unit? processing reads from memory 4-1 the pair of values (USER_ID, Shared Secret) corresponding to the extracted USER_ID value and then identifies the Shared Secret value associated with the extracted USER_ID value.

At instant t29 (following t28) the unit? processing locally generates a TOTP according to the identified Shared Secret value and the value of a time stamp (derived from a reference time and a time step as defined in the RFC6238 standard), using the algorithm defined therein for this generation RFC6238 standard: said generated value of TOTP to network server 4 verr? indicated below with TOTP in reception (to distinguish it from TOTP transmitted previously generated in the opto-electronic key 2).

It is assumed that the time interval between the instant t23 (in which the transmitted TOTP value is generated) and the instant t29 (in which the local TOTP value in reception is generated) is less than the time interval of validity of the time-based once-valid keyword, which? typically equal to 60 seconds, which? sufficient for the subject 6 to carry out the operations of acquiring the fingerprint and pressing a button on the electronic key 2 in order to generate the optical beam F_O towards the lock 3.

At instant t30 (following t29) the unit? of the network server 4 makes a comparison between the local TOTP value (generated at the network server 4) and the transmitted TOTP value (generated at lock 3), then detects that the values of the two TOTPs are equal to each other ; consequently, the unit? network server 4 generates a signal indicative of an authorization to unlock lock 3 and therefore at instant t31 (subsequent to t30) the long-distance signal transceiver of network server 4 transmits the signal a to lock 3 long distance S2_ld carrying a message indicating an authorization to unlock the lock 3 of the vehicle 50.

At instant t32 (subsequent to t31) the transceiver of lock 3 receives the long-distance wireless signal S2_ld which carries the message indicating the authorization to unlock lock 3, therefore the unit? processing of the lock 3 generates a command signal indicative of an unlocking of the lock 3 in an open position, for example by driving the electric motor integrated in the vehicle door 50 and connected with mechanical means which unlock the opening of the door itself.

Preferably, at instant t33 (subsequent to t32) the unit? processing of lock 3 generates a signal indicative of unlocking the opening of lock 3, then the transceiver of lock 3 transmits to the network server 4 the long-distance signal S2_ld which carries a message indicating the unlocking of the lock 3 opening .

At instant t34 (subsequent to t33) the long-distance signal transceiver of the network server 4 receives the long-distance signal S2_ld which carries the message indicating the unlocking of the lock 3 opening and ends the normal operation phase, therefore the subject 6 can? open the vehicle door 50 associated with the lock 3.

Note that for simplicity? yes ? considering the case in which the memory 4-1 of the network server 4 stores a pair of values (KEY_ID, S-KEY) and a pair of values (USER_ID, Shared Secret) because? was considered a single subject 6, but more? in general the memory 4-1? such as to memorize a plurality? of pairs of values (ID_KEY, KEY-S) and a corresponding plurality? of pairs of values (USER_ID, Shared Secret), in which said plurality? corresponds to the number of keys (similar to the opto-electronic key 2) that are authorized to open the door of a vehicle on which? fitted with a lock similar to the opto-electronic lock 3.

With reference to Figures 1, 4A, 4B, 4C, the operation of the electronic system 10 in the mode is shown. offline operation.

In this case not? available the long distance connection between the network server 4 and the lock 3, therefore during the mode? the operations of extracting KEY_ID, USER_ID and TOTP transmitted (instant t38), generation of TOTP in reception (instant t39), comparison between the values of OTP transmitted and OTP in reception (instant t40) and generation of the command lock release 3 (t42) are carried out in lock 3 itself.

Furthermore, the operation of the system 10 in the first part of the configuration phase of the mode? offline differs from online in that at instant t6? the electronic key 2 generates towards the lock 3 the optical beam F_O which carries a message that contains a configuration request and contains the pair of values (ID-KEY, KEY-S) stored in the memory 2-1 of the opto-electronic key 2 .

Subsequently at time t7? lock 3 receives the optical beam F_O which carries said message which contains the configuration request and the pair of values (ID-KEY, KEY-S), therefore at instant t8? the pair of values (ID-KEY, KEY-S) is stored in memory 3-1 that? directly or indirectly connected to the lock 3.

Therefore, at the end of the first part of the configuration phase of the mode? offline the pair of values (KEY-ID, S-KEY)? been memorized in the memory 3-1 associated with the lock 3, in which said pair of memorized values of (ID-KEY, KEY-S) will be used subsequently in the phase of normal operation of the system 10 in the mode? Offline.

Furthermore, the operation of the system 10 in the second part of the configuration phase of the mode? offline differs from online in that at instant t17? (following t13) the electronic key 2 generates towards the lock 3 the optical beam F_O which carries a message containing the pair of values (USER-ID, Shared Secret) generated at instant t13 in the opto-electronic key 2.

Subsequently to the instant t18? lock 3 receives the optical beam F_O which carries said message which contains the pair of values (USER-ID, Shared Secret), therefore at instant t18? the pair of values (USER-ID, Shared Secret) is stored in memory 3-1 that? directly or indirectly connected to the lock 3.

Therefore, at the end of the configuration phase of the mode? offline, the pair of values of (ID-KEY, KEY-S) and the pair of values (ID_USER, Shared Secret) have been stored in the memory 3-1 associated with lock 3, in which said memorized values of (ID- KEY, KEY-S) and (USER_ID, Shared Secret) will be used later in the phase of normal operation of the system 10 in the mode? Offline.

According to a variant of the invention, the Paying Load of the data packet 30 further comprises a third field which contains information representative of one or more? commands representative of one or more? functions to be performed on the vehicle 50, such as opening the trunk, turning on the vehicle headlights 50, turning on the vehicle interior light 5.

In this case the key 2 comprises a further key (separate from the opening / closing key of the lock 3) having the function of generating the command to be executed.

Operation according to said variant? analogous to that described above, with the difference that the function associated with the command in question is activated only after? the authorization to access lock 3 has been granted by the network server 4 (online mode) or by the lock 3 itself (offline mode).

The present invention also relates to a method for controlling the opening of a lock of an access door to a limited environment as defined in the attached method claims.

In the case of modality? for offline operation, the method is carried out by means of a software program which is run partly on an electronic processor (for example, a microcontroller) of the opto-electronic key 2 and partly on an electronic processor (for example, a microprocessor) of the opto-electronic lock 3.

In the case of modality? for on-line operation, the method is carried out by means of a software program which is performed partly on an electronic processor of the opto-electronic key 2, partly on an electronic processor of the opto-electronic lock 3 and partly on an electronic processor (for example, a microprocessor) of the network server 4.

Claims (16)

CLAIMS 1. Electronic system (10) for controlling the opening of a lock of an access door in a confined space, the system comprising an opto-electronic key (2) and an opto-electronic lock (3), in which the opto-electronic key (2) includes a unit? processing, an optical source and a non-volatile memory (2-1) configured to store a configured value of a key identifier (KEY_ID) indicative of a unique identifier associated with the opto-electronic key, a configured value of a user identifier (USER_ID ) and a corresponding configured value of Shared Secret associated with the value of the user ID, in which said configured value of Shared Secret? a string consisting of a defined number of bits, in which the lock includes a unit? processing, an optical receiver and a non-volatile memory (3-1) configured to store a configured value of the user identifier (USER_ID) and a corresponding configured value of Shared Secret associated with the configured value of the user identifier, the unit? processing of the opto-electronic key being configured for: - generate (t22) a value of a user identifier (USER_ID) as a function of data representative of an identity? digital sample of a subject (6) using the opto-electronic key; - read, from the memory (2-1) of the opto-electronic key, the value of the generated user identifier (USER_ID) and the corresponding configured Shared Secret value associated with the value of the generated user identifier; - generate (t23) a Keyword valid only once based on Time (TOTP tx) and valid for a defined time interval, in which the value of said Keyword? generated according to the configured value of the Shared Secret and a time stamp; - read, from the memory (2-1) of the opto-electronic key, the configured key identifier (KEY_ID) and generate a data packet (30) which includes the key identifier (KEY_ID; 30-1), the user identifier (USER_ID; 30-2) and the Time-based once-valid Keyword (TOTP tx; 30-3); the optical source of the opto-electronic key (2) being configured to generate an optical beam (F_O) which carries the data packet (30) which includes the key identifier (KEY_ID), the user identifier (USER_ID) and the Keyword valid once based on Time (TOTP tx), the optical receiver of the lock being configured to receive the optical beam (F_O) which carries the data packet (30) and forward it to the unit? processing, the unit? processing of the lock being configured for: - receive the data packet and extract (t38) from it the value of the key identifier, of the user identifier and of the Key Word valid only once based on Time (TOTP tx); - read, from the memory (3-1) of the lock (3), the value of the configured user ID and the corresponding configured value of Shared Secret associated with the value of the configured user ID; - generate (t39), at the lock, an additional Key Word valid only once based on time (TOTP rx) and valid for a defined time interval, in which said further Key Word? generated as a function of said configured Shared Secret value and a time stamp; - compare (t40) the value of the additional Key Word (TOTP rx) with respect to the value of the extracted Key Word (TOTP tx); - generate a command signal indicative of an authorization granted or denied to the opening / closing of the opto-electronic lock, depending on the positive or negative comparison, respectively. Electronic system (10) according to claim 1, where the memory of the key? further configured to store data representative of an identity? digital reference, in which the key further includes means of acquiring data representative of the identity? digital sample, in particular a reader of a sample fingerprint of the finger of the hand of the subject, and in which the unit? key processing? further configured for: - read, from the memory (2-1) of the opto-electronic key (2), data representative of the identity? digital reference of the subject; - compare the identity? digital sample with respect to the identity? digital reference; - in the event of a positive comparison, read the configured Shared Secret value from the memory (2-1); - in the event of a negative comparison, wait for a new acquisition of the data representative of the identity? digital sample. Electronic system (10) according to claims 1 or 2, in which the memory (2-1) of the opto-electronic key and the memory (3-1) of the lock are further configured to store a configured value of a Symmetric Key (S-KEY) of a symmetric encryption, in which the unit? opto-electronic key processing? further configured to read the configured value of the Symmetric Key (S-KEY) from its memory and perform, according to the value read of the Symmetric Key (S-KEY), an encryption of a Paying Load including the user ID and the Password valid only once based on the Time, generating cos? an encrypted Payload, in which the optical source of the opto-electronic key? further configured to transmit the optical beam (F_O) which carries a data packet (30) which includes the key identifier in clear text and includes the encrypted Payload, in which the optical receiver of the opto-electronic lock (3)? configured to receive the optical beam (F_O) that carries the data packet and extract from it the value of the key identifier (KEY_ID) in clear text and the encrypted Payload, in which the unit? of the opto-electronic lock (3)? configured for: - read, from the memory (3-1) of the opto-electronic lock (3), the value of the extracted key identification and a corresponding memorized value of the Symmetric Key; - perform a decryption of the encrypted Payload by means of the read value of the Symmetric Key and extract the values of the user ID and the Keyword valid only once based on Time (TOTP tx). Electronic system (10) according to claims 1 or 2, the system further comprising a network server (4) comprising a medium-long distance signal transceiver, a unit? and a non-volatile memory (4-1) configured to store a configured value of the user ID (USER_ID) and a corresponding configured value of Shared Secret associated with the configured value of the user ID, the network server being connected to the opto-electronic lock (3) by means of a communication channel through a medium-long distance telecommunications network, in which the optical receiver of the opto-electronic lock (3)? configured to receive the optical beam (F_O) that carries the data packet, without performing the extraction, wherein the opto-electronic lock (3) comprises a medium-long distance signal transceiver configured for: - transmit, to the network server through the telecommunications network (15), a medium-long distance signal (S2_ld) which carries the value of the key identifier (KEY_ID), of the user identifier (USER_ID) and of the Key Word valid once based on Time (TOTP tx); - receive, from the network server, the medium-long distance signal (S2_ld) which carries a message indicating an authorization granted or denied to the opening / closing of the opto-electronic lock and authorizing or inhibiting the opening / closing of the opto lock -electronics, depending on the authorization granted or denied respectively; in which the network server includes a medium-long distance signal transceiver configured to receive (t27) the medium-long distance signal and extract from this the values of the key identifier (KEY_ID), of the user identifier (USER_ID) and of the Time-based once valid Keyword (TOTP tx), and in which the unit? network server processing? configured for: - read, from the memory (4-1) of the network server (4), the value of the extracted user ID and a corresponding stored value of Shared Secret associated with the value of the extracted user ID; - generate (t29) an additional Key Word valid only once based on time (TOTP rx) and valid for a defined time interval, in which said further Key Word? generated as a function of said stored value of Shared Secret and of a time stamp; - compare (t30) the value of the additional Key Word (TOTP rx) with respect to the value of the extracted Key Word (TOTP tx); and where the network server medium-long distance signal transceiver? configured to transmit (t31) to the lock (3) the medium-long distance signal which carries a message indicating an authorization granted or denied to the opening / closing of the opto-electronic lock, according to the positive or negative comparison, respectively. Electronic system (10) according to claim 4, in which the memory (2-1) of the opto-electronic key and the memory (4-1) of the network server (4) are further configured to store a configured value of a Symmetric Key (S-KEY) of a symmetric cryptography , in which the unit? opto-electronic key processing? further configured to read from its memory (2-1) the configured value of the Symmetric Key (KEY-S) and perform, according to the value read of the Symmetric Key (KEY-S), an encryption of a Paying Load including the identification user and the once-valid Keyword based on Time, thus generating an encrypted Payload, in which the optical source of the opto-electronic key? further configured to transmit the optical beam (F_O) which carries a data packet (30) which includes the key identifier (KEY_ID) in clear text and includes the encrypted Payload, where the network server transceiver (4)? configured to receive the medium-long distance signal that carries the data packet and extract from it the value of the key identifier (KEY_ID) in clear text and the encrypted Payload, and in which the unit? network server processing (4)? configured to: - read, from the memory (4-1) of the network server (4), the value of the extracted key identifier and a corresponding stored value of the Symmetric Key; - perform a decryption of the encrypted Payload by means of the read value of the Symmetric Key and extract the values of the user ID and the Keyword valid only once based on Time (TOTP tx). 6. Electronic system according to any one of the preceding claims, wherein: - the identity? digital reference / sample? a biometric profile of the subject, in particular a fingerprint of a finger of the subject's hand acquired by means of a fingerprint reader mounted in the key (2); - the value of the once-time-based Keyword? generated as defined in the RFC6238 standard; - the value of Shared Secret? generated by means of a hash function that takes as input the value of the user identifier (USER_ID) or a combination of the user identifier (USER_ID) and the Symmetric Key (S-KEY), and outputs a string consisting of at least 128 bit. 7. Method for controlling the opening of a lock of a door giving access to a limited environment, the method comprising the steps of: a) generating (t22), to an opto-electronic key (2) outside the room, a value of a user identifier (USER_ID) as a function of data representative of an identity? digital sample of a subject (6) using the opto-electronic key; b) read, from a memory (2-1) of the opto-electronic key, the value of the generated user identifier and a corresponding configured value of Shared Secret associated with the value of the generated user identifier, in which said configured value of Shared Secret ? a string composed of a defined number of bits; c) generate (t23), to the opto-electronic key, a Key Word valid only once based on Time (TOTP tx) and valid for a defined time interval, in which the value of said Key Word? generated according to the configured value of the Shared Secret and a time stamp; d) reading, from the memory (2-1) of the opto-electronic key, a key identifier (KEY_ID) indicative of a unique identifier associated with the opto-electronic key; e) transmit (t24), from the opto-electronic key (2) to an opto-electronic lock (3) positioned inside the room, an optical beam (F_O) carrying a data packet (30) which includes the key identification (KEY_ID; 30-1), the user ID (USER_ID; 30-2) and the Keyword valid once based on Time (TOTP tx; 30-3); f) receiving, at the lock (3), the optical beam and extracting (t38) from it the value of the key identifier, of the user identifier and of the Key Word valid only once based on Time (TOTP tx); g) reading, from a memory (3-1) of the lock (3), the value of the extracted user ID and a corresponding configured value of Shared Secret associated with the value of the extracted user ID; h) generate (t39), at the lock, an additional Key Word valid only once based on time (TOTP rx) and valid for a defined time interval, in which said further Key Word? generated as a function of said configured Shared Secret value and a time stamp; i) compare (t40) the value of the further Key Word (TOTP rx) with respect to the value of the extracted Key Word (TOTP tx); j) authorize or inhibit the opening / closing of the optoelectronic lock, according to the positive or negative comparison, respectively. Method according to claim 7, wherein: step a) includes: - acquire data representative of the identity? sample fingerprint, in particular a sample fingerprint of a finger of the subject's hand; - read, from the memory (2-1) of the opto-electronic key (2), data representative of an identity? reference finger of the subject, in particular a reference fingerprint of the finger of the hand of the subject; - compare the identity? digital sample with respect to the identity? digital reference; - in case of a positive comparison, continue with step b); - in the event of a negative comparison, wait for a new acquisition of the data representative of the identity? digital sample. 9. Method according to claims 7 or 8, where step e) further includes, before transmission: - reading, from the memory (2-1) of the optoelectronic key (2), a configured value of a Symmetric Key (S-KEY) of a symmetric cryptography; - perform, according to the value read of the Symmetric Key (S-KEY), an encryption of a Paying Load including the user ID and the Keyword valid only once based on Time, thus generating? an encrypted Payload; and in which in step e) said transmission comprises transmitting the optical beam (F_O) which carries a data packet (30) which comprises the key identifier in clear text and comprises the encrypted Payload; where step f) includes: - receive, from the opto-electronic lock (3), the optical beam (F_O) that carries the data packet and extract from this the value of the key identification (ID_KEY) in clear text and the encrypted Payload; - read, from the memory (3-1) of the opto-electronic lock (3), the value of the extracted key identification and a corresponding memorized value of the Symmetric Key; - perform a decryption of the encrypted Payload by means of the read value of the Symmetric Key and extract the values of the user ID and the Keyword valid only once based on Time (TOTP tx). Method according to claim 7 or 8, comprising, instead of steps g) -j), the steps of: g1) transmit, from the lock (3) to a network server (4) through a telecommunications network (15), a medium-long distance signal (S2_ld) which carries the value of the key identifier (ID_KEY), of the? user identifier (USER_ID) and the Keyword valid only once based on Time (TOTP tx); g2) receive (t27), to the network server, the medium-long distance signal and extract from this the values of the key identifier (KEY_ID), of the user identifier (USER_ID) and of the Keyword valid only once based on the Time (TOTP tx); g3) reading, from a memory (4-1) of the network server (4), the value of the extracted user identifier and a corresponding stored value of Shared Secret associated with the value of the extracted user identifier; h1) generate (t29), to the network server (4), an additional Keyword valid only once based on time (TOTP rx) and valid for a defined time interval, in which said further Keyword? generated as a function of said stored value of Shared Secret and of a time stamp; i1) compare (t30) the value of the further Key Word (TOTP rx) with respect to the value of the extracted Key Word (TOTP tx); i2) transmit (t31), from the network server to the lock, the medium-long distance signal that carries a message indicating an authorization granted or denied to the opening / closing of the opto-electronic lock, depending on the comparison, respectively positive or negative; j1) receive (t32), at the lock, the medium-long distance signal and authorize or inhibit the opening / closing of the opto-electronic lock, according to the authorization granted or denied respectively. Method according to claim 10, wherein: where step e) further includes, before transmission: - reading, from the memory (2-1) of the opto-electronic key (2), a configured value of a Symmetric Key (S-KEY); - perform, according to the value read of the Symmetric Key (S-KEY), an encryption of a Paying Load including the user ID and the Keyword valid only once based on Time, thus generating? an encrypted Payload; and in which in step e) said transmission comprises transmitting the optical beam (F_O) which carries a data packet (30) which includes the key identifier (KEY_ID) in clear text and includes the encrypted Payload; where step g2) includes: - receive, from the network server (4), the medium-long distance signal that carries the data packet and extract from this the value of the key identifier (KEY_ID) in clear text and the encrypted Payload; - read, from the memory (4-1) of the network server (4), the value of the extracted key identifier and a corresponding memorized value of the Symmetric Key; - perform a decryption of the encrypted Payload by means of the read value of the Symmetric Key and extract the values of the user ID and the Keyword valid only once based on Time (TOTP tx). 12. Non-transient storage medium readable by a computer having a program comprising portions of software code suitable for carrying out steps a) -d) or steps f) -j), j1) or steps g1), g2), g3), h1), i1), i2) of the method according to claims 7-11, when said program? performed on at least one computer. Motor vehicle comprising an electronic system according to any one of claims 1-6, in which the vehicle includes: - a surface at least partially transparent with respect to an optical beam, in particular a glass of a window of a vehicle door; or - a through hole in the door, in particular comprising an optical fiber positioned along the hole; where the opto-electronic lock (3)? mounted inside the vehicle interior so that an optical path is defined between the optical source of the key, when this? positioned externally to the vehicle, and the optical receiver of the lock (3), crossing the at least partially transparent surface or the through hole. 14. Opto-electronic key (2) to control the opening of a lock of an access door in a confined space, the key comprising a unit? processing, an optical source and a non-volatile memory (2-1), where the memory (2-1)? configured to store a configured value of a key identifier (KEY_ID) indicative of a unique identifier associated with the opto-electronic key, a configured value of a user identifier (USER_ID) and a corresponding configured Shared Secret value associated with the value of the user identifier , where said Shared Secret configured value? a string consisting of a defined number of bits, in which the unit? processing? configured for: - generate (t22) a value of a user identifier (USER_ID) as a function of data representative of an identity? digital sample of a subject (6) using the opto-electronic key; - read, from the memory (2-1) of the opto-electronic key, the value of the generated user identifier (USER_ID) and the corresponding configured Shared Secret value associated with the value of the generated user identifier; - generate (t23) a Keyword valid only once based on Time (TOTP tx) and valid for a defined time interval, in which the value of said Keyword? generated according to the configured value of the Shared Secret and a time stamp; - read, from the memory (2-1) of the opto-electronic key, the configured key identifier (KEY_ID) and generate a data packet (30) which includes the key identifier (KEY_ID; 30-1), the user identifier (USER_ID; 30-2) and the Time-based once-valid Keyword (TOTP tx; 30-3); and in which the optical source of the opto-electronic key (2)? configured to generate an optical beam (F_O) carrying the data packet (30) which includes the key identifier (KEY_ID), the user identifier (USER_ID) and the Time-based once-only-valid Keyword (TOTP tx). 15. Opto-electronic lock (3) to command the opening of a door giving access to a limited environment, the lock comprising a unit? processing, an optical receiver and a non-volatile memory (3-1), in which the memory (3-1)? configured to store, in case of operation in a mode? offline, a configured value of a user identifier (USER_ID) and a corresponding configured value of Shared Secret associated with the configured value of the user identifier, in which, in case of operation in the mode? offline, the optical receiver of the lock? configured to receive an optical beam (F_O) carrying a data packet (30) which includes a key identifier (KEY_ID), user identifier (USER_ID) and a Time-based once-valid Keyword (TOTP tx), and ? configured to forward it to the unit? processing, in which, in case of operation nela mode? offline, the unit? processing of the lock? configured for: - receive the data packet and extract (t38) from it the value of the key identifier, of the user identifier and of the Key Word valid only once based on Time (TOTP tx); - read, from the memory (3-1) of the lock (3), the value of the configured user ID and the corresponding configured value of Shared Secret associated with the value of the configured user ID; - generate (t39) an additional Key Word valid only once based on time (TOTP rx) and valid for a defined time interval, in which said further Key Word? generated as a function of said configured Shared Secret value and a time stamp; - compare (t40) the value of the additional Key Word (TOTP rx) with respect to the value of the extracted Key Word (TOTP tx); - generate a command signal indicative of an authorization granted or denied to the opening / closing of the opto-electronic lock, according to the positive or negative comparison, respectively; and in which, in case of operation in the mode? in line, the opto-electronic lock (3) further comprises a medium-long distance signal transceiver, in which, in case of operation in the mode? online, the optical receiver of the lock? configured to receive an optical beam (F_O) carrying a data packet (30) which includes a key identifier (KEY_ID), user identifier (USER_ID) and a once-valid Time-based Keyword (TOTP tx), where the medium-long distance signal transceiver? configured for: - transmit a medium-long distance signal (S2_ld) which carries the value of the key identifier (KEY_ID), of the user identifier (USER_ID) and of the Key Word valid only once based on Time (TOTP tx); - receive the medium-long distance signal (S2_ld) which carries a message indicating an authorization granted or denied to the opening / closing of the opto-electronic lock and authorizing or inhibiting the opening / closing of the opto-electronic lock, depending on the authorization granted or denied respectively. 16. Network server (4) to control the opening of a lock of an access door of a limited environment, the server comprising a medium-long distance signal transceiver, a unit? and a non-volatile memory (4-1) configured to store a configured value of a user identifier (USER_ID) and a corresponding configured value of Shared Secret associated with the configured value of the user identifier, where the medium-long distance signal transceiver? configured for: - receive (t27) a medium-long distance signal (S2_ld) which carries values of a key identifier (KEY_ID), of the user identifier (USER_ID) and of a Key Word valid only once based on Time (TOTP tx); - extract the values of the key identifier (KEY_ID), of the user identifier (USER_ID) and of the Keyword valid only once based on Time (TOTP tx); in which the unit? network server processing? configured for: - read, from the memory (4-1) of the network server (4), the value of the extracted user ID and a corresponding stored value of Shared Secret associated with the value of the extracted user ID; - generate (t29) an additional Key Word valid only once based on time (TOTP rx) and valid for a defined time interval, in which said further Key Word? generated as a function of said stored value of Shared Secret and of a time stamp; - compare (t30) the value of the additional Key Word (TOTP rx) with respect to the value of the extracted Key Word (TOTP tx); and where the network server medium-long distance signal transceiver? configured to transmit (t31) the medium-long distance signal which carries a message indicative of an authorization granted or denied to the opening / closing of an opto-electronic lock, depending on the positive or negative comparison, respectively.