EP2500872A1 - Secured method for controlling the opening of locking devices by means of a communication object such as a mobile phone - Google Patents

Abstract

The method involves transmitting the message from a communication device (16) to a reading interface (20) coupled to a lock device (18). The message is analyzed within the reading interface by decrypting the data field. The consistency of the time marker contained in the data field is checked with an inner clock (26) of the reading interface. A digital accreditation stored in memory in the interface is sent from the interface to the lock device, and the lock device unlocking upon recognizing the compliance of digital accreditation in case of compliant message, is operated.

Description

The invention relates to lock devices electrically controlled by means of a dematerialized and encrypted key, this key can be conveyed by a portable object held by the user such as a mobile phone, a badge or a contactless card, etc. .

By "lock device" is meant not only a lock stricto sensu, that is to say a mechanism placed for example on a door to condemn the opening, but also any device to achieve a comparable result, for example a lock gun considered in isolation, or a more specific locking device comprising various members not grouped in the same lock box, the ultimate goal being to obtain the conviction by mechanical means of physical access to a place or given space, and access to this place or space by unlocking the lock device, on the order of a user, after verification that this user has access rights (i) that are specific to him and (ii) who are specific to the lock device. The lock device may also include, or be associated with, an alarm system that is to disable to allow access to a given space, or conversely activate to protect this space before or after the to have left. For simplicity of description, we will speak later simply "lock", but this term must be understood in its broadest sense, without any restrictive character to a particular type of equipment.

The portable object, when approaching the lock, plays the role of a key to control the opening. Numerous systems are known for coupling the portable object to the lock by galvanic means (smart card contacts) or non-galvanic (portable object inductive coupling or RFID type card). This coupling ensures between lock and badge communication allowing in particular the lock to read in the memory of the badge accreditation data to control the opening if this data is recognized as compliant. Instead of a dedicated badge, a mobile phone equipped with a Near Field Communication ( NFC) chip and an NFC antenna can also be used, the UICC (Universal Integrated Circuit Card) corresponding to the "SIM card" for the GSM telephony functions) of the telephone that can be used as a security element. The setting in communication phone with a manager site makes it easy to check online, change security features or download new ones, etc.

The WO 2011/010052 (Openways SAS) proposes a technique that can be used with any conventional mobile phone, not necessarily equipped with NFC circuits, and without the need for a dedicated additional portable object such as a badge or card. This technique relies on the use of Crypto Acoustic Credential ( CAC) encrypted acoustic accreditations in the form of single-use audio signals, for example consisting of a succession of dual DTMF tones. These acoustic accreditations can be generated by a secure remote site and transmitted over the telephone by usual telephone transmission channels (voice or data), via the Mobile Network Operator ( MNO ) and a TSM trusted service provider ( Trusted Service Manager).

To use the accreditation, the user approaches his phone lock and triggers the transmission by the speaker of his phone in the series of tones corresponding to encrypted acoustic accreditation, so that these tones can be captured by a microphone incorporated or coupled to the lock. The latter decodes the accreditation, verifies it and, in case of conformity, unlocks the mechanical parts.

European demand EP 09 170 475.9 of September 16, 2009, on behalf of Openways SAS for a "system of secure management of locks numerically controlled, adapted to operation by encrypted acoustic accreditations" more precisely describes the technique used. This consists in using the original DDC (Digital Data Credential) digital data accreditations, specific to the manufacturer of the lock, preserving them with their content and their own format, and converting them into Acoustic Accreditations CAC. In pictorial terms, the cryptographic engine of the secure site creates an acoustic "envelope" in which the preexisting DDC digital accreditation is "dragged", and this independently of the content of the latter because the cryptographic engine does not need to know the definition. fields, coding, etc., of DDC accreditation.

The acoustic accreditation generated in this way is transmitted to the mobile phone to be reproduced by the latter in front of the lock.

The acoustic signal picked up by the lock is the object of an inverse conversion, making it possible to restore the accreditation in original DDC digital data from the CAC acoustic accreditation detected and analyzed. In other words, the acoustic module of the lock "opens the envelope" (the acoustic accreditation CAC) to extract intact DDC digital information that had previously been placed in this envelope by the cryptographic engine of the remote site , all without intervention on the contents of this digital accreditation DDC.

This technique is particularly effective and safe. In particular, the fact that it is the same third party source (the manufacturer / manager of the lock) that generates all DDC digital accreditations ensures secure identification of the authorized users, whatever the method of issuing the accreditation: either by the phone in the form of acoustic accreditation CAC, otherwise by reading a card or a specific badge, for example.

However, it has several disadvantages.

First of all, the generation of acoustic accreditation requires an interfacing of the third-party source (which owns and delivers the DDC digital accreditation) with the remote site's cryptographic engine (which generates the acoustic accreditations CAC). This interfacing is always rather difficult to implement, and specific to each third source, hence the additional costs of setting up the system.

Secondly, DDC Digital Accreditation is a relatively large message because it has to carry a lot of information, especially when it is to be used with standalone locks. The DDC accreditation message must indeed be able to manage various functions such as the revocation of old authorizations, the updating of the list of authorized users stored in the lock, etc. DDC digital accreditation may also include specific data, for example necessary to verify correct reading of a dedicated card or badge, but which will be of no use if the accreditation is issued via a mobile phone through a CAC Acoustic Accreditation. As a result, the transmission of accreditation from the phone to the lock device can take a relatively long time compared to reading a simple dedicated badge, and this in a useless way.

• aucune nécessité d'interfaçage avec le serveur d'une source tierce ;
• utilisation de la même technique avec tous les dispositifs de serrures, quels que soient leurs fabricants ;
• utilisation de messages relativement compacts, donc pouvant être transmis en un temps très bref ;
• possibilité de prévoir néanmoins des critères d'utilisation tels que : horaires d'accès limités, date d'expiration, accès à une ou plusieurs portes pour un utilisateur donné, etc. ;
• avec des serrures autonomes, possibilité de révoquer des autorisations antérieures données à d'autres utilisateurs avec des badges dédiés, même si cette habilitation n'est pas expirée.

The aim of the invention is to propose a technique which, with the same level of security as that which has just been described, avoids the use of a digital accreditation generated by a third source, with the following correlative advantages. :

• no need for interfacing with the server of a third party source;
• use of the same technique with all lock devices, regardless of their manufacturers;
• use of relatively compact messages, which can be transmitted in a very short time;
• However, it is possible to provide usage criteria such as: limited access times, expiration date, access to one or more doors for a given user, etc. ;
• with autonomous locks, possibility to revoke previous authorizations given to other users with dedicated badges, even if this authorization is not expired.

Another object of the invention is, in the case of autonomous locks, to resynchronize the internal clock of this lock.

Indeed, insofar as a large part of the system's security is based on the management of the obsolescence in the time of the authorizations, it is important to correct the problems related to the drift of the internal clocks of the locks which, in particular in certain temperature conditions may have a significant impact that may prevent the system from functioning properly. It is therefore important to be able to take into account this drift and readjust the internal clock of the lock on a reference clock with which it must be synchronized.

Another object of the invention is to allow the use of unsecured coupling technologies - thus easy to implement - between the telephone and the lock, and to overcome the complexity of secure coupling systems generally used. in access control applications.

A typical example of unsecured coupling is the "peer to peer" mode in NFC which, unlike the "card emulation" mode, does not use not the security elements of the phone (SIM card or other security element) and is therefore not dependent on the mobile network operator MNO who issued the security element and is likely to control its use.

Indeed, as will be seen, the invention does not seek to prevent the interception or duplication of signals exchanged between the lock and the telephone (or the badge, card, ...), but only to render inoperative a accreditation that has been duplicated or reconstituted (for example by reverse engineering) and fraudulently applied to the lock. The basic idea of the invention is to ensure that the digital accreditation of the third source, which makes it possible to unlock the lock, is no longer located in the "envelope", but in an interface module. reading coupled to the lock, for example in the firmware (firmware) of this module.

Therefore, it will no longer be necessary to interface the portable object (mobile phone or other) with the third party source, and no need to put a content in the envelope. This may be empty, that is to say that it will not contain a third party key such as a DDC type digital accreditation as in the previous system.

Thus, the size of the information to be transmitted can be reduced in significant proportions. In particular applications the size of the envelope can be adapted to convey specific information (authorized hours, expiry date, etc.) but in any case the size can be reduced and optimized according to the real needs of system complexity, so as to reduce the transmission to the single envelope, without DDC content.

The reading interface module will only check the validity of the envelope and transmit to the lock the accreditation stored in memory (in the module) for controlling the unlocking of the lock.

The conformity check of the invention is based on a timestamp or equivalent technique (sequential counter), implemented from data contained in a field of the envelope, the value of which will be compared with a horizontal internal clock of the horizontal type. real-time clock ( RTC ), or an internal counter of the interface module. In the case of autonomous lock devices, 1 "" opening "of the envelope by the interfacing module may advantageously control the resetting of the internal clock of the module, so as to avoid excessive drift of this internal clock.

Still in the case of autonomous devices, the opening of the envelope may also control the revocation of any previous authorization of opening given to a user. For example, in the case of a hotel application, the opening of the door by a new customer holding a portable object (mobile phone or other) will automatically revoke any authorization given to a previous customer, even if this authorization does not apply. is not expired, and this without having to reprogram the lock.

In any case, and unlike conventional badge or key systems, this is not to prevent the duplication of an envelope, but only to render a duplicate envelope inoperative. It will thus be possible to use unsecured, simple and secure coupling technologies between the portable object (telephone or badge) and the interface for reading the lock.

1. a) générer par un logiciel applicatif un message formant clef, ce message comprenant un champ de données crypté contenant un marqueur temporel, ce marqueur temporel étant un marqueur d'horodatage par une horloge de référence couplée au logiciel applicatif, ou un marqueur de séquencement incrémenté par le logiciel applicatif ;
2. b) transférer le message à un dispositif de communication portable, détenu par un utilisateur ;
3. c) transmettre le message, par une technique de transmission à courte portée, du dispositif de communication à une interface de lecture couplée à un dispositif de serrure ;
4. d) analyser le message au sein de l'interface de lecture par décryptage du champ de données, et vérification de la cohérence du marqueur temporel contenu dans le champ de données avec une horloge interne de l'interface de lecture dans le cas d'un marqueur d'horodatage, ou avec un numéro de séquence mémorisé dans l'interface de lecture dans le cas d'un marqueur de séquencement ; et
5. e) en cas de message avéré conforme à la suite des vérifications de l'étape d), envoyer de l'interface de lecture au dispositif de serrure une accréditation numérique, conservée en mémoire dans l'interface de lecture, propre à commander le déverrouillage du dispositif de serrure sur reconnaissance de la conformité de cette accréditation numérique.

More precisely, the invention proposes a process characterized by the following steps:

1. a) generating, by an application software, a key message, this message comprising an encrypted data field containing a time marker, this time marker being a timestamp marker by a reference clock coupled to the application software, or an incremented sequencing marker; by the application software;
2. b) forwarding the message to a portable communication device held by a user;
3. c) transmitting the message, by a short-range transmission technique, of the communication device to a read interface coupled to a lock device;
4. d) analyzing the message within the reading interface by decrypting the data field, and checking the coherence of the time marker contained in the data field with an internal clock of the reading interface in the case of a timestamp marker, or with a sequence number stored in the read interface in the case of a sequencing marker; and
5. e) in the event of a confirmed message conforming to the sequence of verifications in step d), sending from the read interface to the lock device a digital accreditation, stored in the read interface, capable of controlling the unlocking of the lock device on recognition of the conformity of this digital accreditation.

Very advantageously, the message generated in step a) further comprises a field containing an encryption method identifier, and the data field is encrypted by said encryption method, and step d) further comprises a reading of the encryption method identifier in the unencrypted field, and the decryption of the data field is performed by applying the encryption method read.

The field containing the encryption method identifier is preferably an unencrypted field, or encrypted according to a predetermined encryption. In step a) the application software selects the encryption method identified in the message from among a plurality of possible encryption methods, said selection being operated in a pseudo-random manner according to a predetermined secret algorithm; and in step d), after reading the encryption method identifier in the unencrypted field, the read interface selects, by implementing a predetermined secret matching algorithm, the method to be used for the decrypting the data field among a plurality of methods stored in memory.

• lorsque le marqueur temporel est un marqueur d'horodatage par une horloge couplée au logiciel applicatif, il est prévu en outre une étape consistant à recaler l'horloge interne de l'interface de lecture à partir du marqueur temporel lu dans le champ de données ;
• lorsque le marqueur temporel est un marqueur de séquencement, il est prévu en outre, en cas de message avéré conforme suite aux vérifications de l'étape d), une étape consistant à mettre à jour le numéro de séquence mémorisé dans l'interface de lecture à partir du marqueur temporel lu dans le champ de données ;
• il est prévu en outre, en cas de message avéré conforme suite aux vérifications de l'étape d), une étape consistant à invalider, si elle est présente, une précédente habilitation relative à un utilisateur antérieur, stockée dans l'interface de lecture ;
• l'étape a) est exécutée au sein d'un serveur distant intégrant le logiciel applicatif ;
• le dispositif de communication est un téléphone portable, et l'étape a) est exécutée au sein du dispositif de communication par une midlet interne intégrant le logiciel applicatif ;
• le champ de données crypté contient en outre des conditions spécifiques d'autorisation d'accès, et l'étape d) comprend en outre une sous-étape de vérification de la conformité des conditions spécifiques d'autorisation d'accès lues dans le champ de données ;
• l'étape c) de transmission du message du dispositif de communication à l'interface de lecture est une transmission sans contact galvanique par un moyen du groupe formé par : transmission de signaux acoustiques ; transmission inductive NFC, notamment en mode peer-to-peer ; transmission radiofréquence, notamment Bluetooth ; transmission de signaux lumineux, notamment IR ; transmission de vibrations par contact mécanique.

According to various advantageous subsidiary features:

• when the time marker is a timestamp marker by a clock coupled to the application software, there is further provided a step of resetting the internal clock of the read interface from the time marker read in the data field;
• when the time marker is a sequencing marker, it is furthermore provided, in the event of a message that is conforming to the verifications of step d), a step of updating the sequence number stored in the reading interface from the time marker read in the data field;
• it is furthermore provided, in the event of a message that is confirmed as a result of the verifications in step d), a step of invalidating, if it is present, a previous prior user authorization stored in the read interface;
• step a) is executed within a remote server integrating the application software;
• the communication device is a mobile phone, and the step a) is executed within the communication device by an internal midlet integrating the application software;
• the encrypted data field further contains specific access authorization conditions, and the step d) further comprises a substep of verifying the compliance of the specific access authorization conditions read in the access control field. data;
• step c) of transmitting the message of the communication device to the reading interface is a transmission without galvanic contact by means of the group formed by: transmission of acoustic signals; inductive NFC transmission, especially in peer-to-peer mode ; radio transmission, in particular Bluetooth; transmission of light signals, especially IR; transmission of vibrations by mechanical contact.

• La Figure 1 est une représentation schématique des différents éléments impliqués dans la mise en oeuvre de l'invention.
• La Figure 2 illustre la structure du bloc de données utilisé par le procédé de l'invention.

An embodiment of the device of the invention will now be described with reference to the appended drawings in which the same reference numerals designate identical or functionally similar elements from one figure to another.

• The Figure 1 is a schematic representation of the various elements involved in the implementation of the invention.
• The Figure 2 illustrates the structure of the data block used by the method of the invention.

The invention is based on the use of messages hereinafter designated DKE (Digital Key Envelope). These DKE messages are generated by an application software SWA (SoftWare Application) symbolized by the block 10 on the Figure 1 , in particular on the basis of a reference clock 12 and / or a sequence counter 14.

The DKE messages are transmitted, by various modes that will be explained below, to communication devices CD (Communication Device) referenced 16, which can be constituted by a mobile phone, a dedicated remote control, a computer system, etc.

As a variant, the application software SWA can be integrated in the communication device CD 16, or in another computing device, since it makes it possible to implement the temporal reference constituted by the clock 12 and / or the sequence counter 14 to securely identify the communication device 16 receiving and using the DKE message.

The message DKE consists of a data flow intended to allow the opening of the lock device 18. This message is transmitted by the communication device CD 16 to an interfacing module 20, called ERED (Envelope Reading Electronic Device) , forming part of the lock device 18.

The coupling between the communication device 16 and the lock device 20 can be operated by various well-known techniques such as acoustic transmission, inductive coupling of the NFC type (in particular in peer-to-peer mode ), Bluetooth coupling , other coupling. radio frequency, infrared coupling, light coupling, vibration coupling, etc., this coupling having no need to be secured, as mentioned above.

Typically, the DKE message does not carry DDC type digital accreditation issued by a third party source (lock manufacturer), and it is the DKE message that itself becomes an accreditation, even in the absence of digital accreditation conveyed by the message.

The interface 20 checks the integrity and the validity of the DKE message it receives and sends a CMD command to the lock, including an unlock command (OPEN), but also a revocation command of a given authorization to a user previous (CANCEL), or any other command useful to the management of the lock device.

The interface 20 is software that is implemented by a microcontroller 22 and a receiving circuit 24 adapted to receive the DKE message that is transmitted to it by one of the coupling modes mentioned above. The microcontroller 22 is also connected to an internal RTC real time clock 26 (independent or included in the microcontroller 22), specific to the interface 20 and / or to a sequence counter 28, so as to have a time reference which will be compared with the time reference of the SWA application software 10 (clock 12 and / or sequence counter 14), after the latter has been transmitted via the DKE message and received by the microcontroller 22. The interface 20 also comprises a memory 30 enabling in particular to manage the various decryption operations of the received DKE message.

The lock device 20 may also be designed to be used in combination with dedicated keys or badges acting as physical accreditation, that is to say that the detection of such a badge will be considered as an authorization given to the wearer. of this badge.

The transmission of the DKE message from the application software 10 to the communication device CD 16 can be carried out in different ways.

A first mode of transmission is a real-time mode "online", with immediate and direct transmission at the time of use, that is to say when the opening of the lock is requested.

Alternatively, the transmission can also be performed by a method of "call back" type where the user makes telephone contact with a remote site, which does not respond immediately but after hang up rings the mobile phone for the user establish contact with the site again, and that is when the DKE message is delivered.

This "online" mode is particularly simple to implement, since it suffices to use, for example, an existing mobile telephone network infrastructure (voice or data), without prior adaptation of the telephone and without any prior intervention on the telephone. -this.

Another advantage lies in the ability to check in real time that the phone belongs to an authorized user, with the possibility of immediately taking into account a "blacklist" of users.

In addition, thanks to this online mode, it is possible to have at a remote site a large amount of information on the use made of the message, including the date and time of use, and eventually the geographical location of the user by identifying the cell of the network from which emanates the user's call.

In particular, since there is bidirectional communication between the lock and the remote server (via the interface module ERED 20 and the communication device CD 16 coupled in peer-to-peer mode ) it becomes possible to trace back to the server information confirming the proper use of the DKE message and the actual opening of the lock, all with indication of the date and time of use, the identity of the lock, the one the CD communication device used, etc.

Another feature available with the online mode is the ability to program or reprogram the lock. For this purpose, when the communication device CD 16 is coupled to the remote server via the interfacing module ERED 20, the system reads the identifier UID (Unique IDentifier) stored in the lock (identifier which is uniquely assigned and allows uniquely identify the lock) and transmit it to the server, possibly after it has been added an explicit abbreviated name ("cave", "garage", service door ", etc.) given by the user by means of the communication device After the usual checks, the server will send back, in the data field of the DKE message, the (re) programming data of the lock.

The reading and sending to the server of the unique identifier UID of the lock can also be used for a simplified implementation of the opening command. Indeed, since the server has a lock identifier, that it can check and compare the corresponding information it holds in its database, it is possible for this server to locate in real time the user when he requests the opening of the lock by sending a request to the server. Once the usual checks have been made, the server will be able to send back a DKE message authorizing the opening of this particular lock, but containing only the information strictly necessary for this opening. The size of the message, and the time necessary for its transmission, can be reduced in this way in significant proportions.

The online mode thus offers a significant number of potentialities, thanks to the possibility of establishing a direct bidirectional link between the lock and the server.

On the other hand, this mode implies having access to the mobile network, which is not always possible (underground car parks, uncovered areas, etc.).

Another mode of transmission, "offline", is used especially if access to the network is not assured at the time of use.

In this case, the communication device CD connects in advance to the remote site and receives from it a predetermined number of DKE messages generated by the SWA application software at the remote site. These DKE messages are stored securely in the phone. At the time of use, the user launches a built-in application on his phone that searches for the first DKE message among those that have been stored, and forwards it to the lock interface, then deletes it from memory, and so continued for the following messages.

Each of the generated and stored DKE messages is uniquely individualized by a time stamp in the form of a different sequence number, in order to render inoperative a DKE that would have been duplicated or reconstructed (this aspect will be developed below in detail). Advantageously, the DKE message also comprises an auxiliary sequence number which is the same for all the DKEs sent to the same communication device CD during the same download and storage session of DKE. If the lock detects an incrementation of this auxiliary number, it will interpret this modification as a change of user, and may then order the revocation of any authorization given to a previous user and stored in the memory of the read interface 20 (purge previous authorizations). The application allowing this implementation is a midlet stored in the phone, previously sent to it by the mobile network operator, or downloaded or received via an Internet connection. When the supply of DKE messages stored in the phone is exhausted, or is running out, and the user is able to access the network again, this message pool will be reloaded for future use.

The Figure 2 illustrates the basic structure of a DKE message.

It comprises two zones, an unencrypted zone I, or encrypted with a method known in advance, and an encrypted zone II containing DATA data and a time marker such as a TS timestamp or a sequence number SEQ. .

Zone I contains an encryption method flag CM, which refers to a method chosen from among several different possible methods, zone II having been encrypted by the SWA application software 10 by means of the selected method indicated in the CM field of the method. zone I.

Advantageously, the encryption method used to encrypt the zone II is modified with each generation of a new DKE message by the SWA application software 10, and the selection of the CM encryption method is performed by a pseudo-random generation algorithm, so as to make unpredictable the determination of the encryption method that will be chosen. Encryption methods can be as well known methods as AES, 3DES, etc., as "proprietary" encryption methods specific to the system designer.

When it receives the DKE message, the interface 20 reads in the field I the CM indicator of encryption method used, selects from among several algorithms that corresponding to the CM method read in the DKE message, and decrypts the zone II by this method, in order to deliver in clear the data fields DATA and time marker TS / SEQ.

The length of the DKE message can be a fixed length (static message) or variable (dynamic message).

• identification du site où se trouve la ou les serrures que l'utilisateur est autorisé à ouvrir ;
• identification de la porte ou des portes du site que l'utilisateur est autorisé à ouvrir ;
• en-tête indiquant qu'il s'agit d'un message statique et donnant sa longueur ;
• dans le cas d'un horodatage, écart maximal autorisé entre l'horodatage donné par l'interface au moment de l'ouverture et l'horodatage contenu dans le message ;
• nombre limité d'ouvertures autorisées d'une même porte ;
• nombre limité d'ouvertures de porte du site, etc.

In the case of a static message, corresponding to the simplest configuration, the data field DATA may include the following information:

• identification of the site where the lock (s) the user is authorized to open is;
• identification of the door or doors of the site that the user is authorized to open;
• header indicating that it is a static message and giving its length;
• in the case of a timestamp, the maximum allowed difference between the time stamp given by the interface at the time of opening and the time stamp contained in the message;
• limited number of authorized openings of the same door;
• limited number of door openings in the site, etc.

• accès à la porte n° 1, n° 2, ..., n° n ;
• accès aux portes dont le numéro est compris dans la plage x à y ;
• date d'expiration de l'autorisation, etc.

In the case of a dynamic message, it is possible to extend the data field (the length being indicated in the header) to take into account information such as:

• access to the door n ° 1, n ° 2, ..., n ° n;
• access to doors whose number is in the range x to y ;
• expiry date of the authorization, etc.

The validity of the DKE message is controlled by comparing the information contained in the TS / SEQ field of the received message (information that reflects the state of the reference clock 12 and / or the counter 14 associated with the application software 10 that has generated the message) with the value of the real-time clock 26 and / or the sequence counter 28 of the interface 20.

A comparison between the clocks 12 and 26 is conceivable only in the case of a direct online transmission of the DKE message from the SWA application software 10 to the interface 20. The consistency between the values of the two clocks is appreciated to a near uncertainty, necessary because of the possible drift of the real-time clock 26 of the interface 20 which belongs to an autonomous device, this tolerance being able to be predetermined, or specified in a field of the DKE message. Furthermore, if the DKE message is compliant, the clock 26 is reset to the reference clock 12, that is to say, the timestamp data TS contained in the DKE message.

The consistency check between the sequence counters 14 and 28 is however applicable in all cases, and in particular when the DKE message is not transmitted in real time. The sequencing follows a predetermined algorithm (linear or not), known only SWA application software 10 and interface 20. In case of consistency between the sequence counters 14 and 28, the counter 28 is updated, giving it the value of counter 14 read in the DKE message.

In case of conformity of the time stamp and / or the sequence counter, the interface 20 issues a digital CMD accreditation to the lock itself 18 to open it ( OPEN command ). Advantageously, the valid opening command is followed by an invalidation command (CANCEL) of any authorization previously given to a different user, which would still be present in the lock device.

Claims (11)

A secure method of controlling the opening of lock devices, characterized by the following steps: a) generating, by an application software (SWA), a key message (DKE), this message comprising an encrypted data field containing a time marker, this time marker being a time-stamping marker by a reference clock coupled to the application software, or a sequencing marker incremented by the application software; b) transfer the message to a portable communication device (CD) held by a user; c) transmitting the message, by a short-range transmission technique, of the communication device to a read interface (ERED) coupled to a lock device (LOCK); d) analyze the message within the reading interface by: - decryption of the data field, and checking the coherence of the time marker contained in the data field with an internal clock of the reading interface in the case of a timestamp marker, or with a sequence number stored in the reading interface in the case of a sequencing marker; and e) in the event of a confirmed message conforming to the following checks of step d), sending from the reading interface to the lock device a digital accreditation (OPEN), able to control the unlocking of the lock device on recognition of the compliance of this digital accreditation. The process of claim 1 wherein: the message generated in step a) further comprises a field containing an encryption method identifier (CM), and the data field is encrypted by said encryption method, and - Step d) further comprises a reading of the encryption method identifier in the unencrypted field, and the decryption of the data field is operated by applying the encryption method read. The method of claim 2 wherein the field containing the encryption method identifier is an unencrypted field, or encrypted according to a predetermined encryption. The process of claim 2 wherein: in step a) the application software selects the encryption method identified in the message from among a plurality of possible encryption methods, said selection being operated in a pseudo-random manner according to a predetermined secret algorithm; and in step d), after reading the encryption method identifier in the unencrypted field, the reading interface selects, by implementing a predetermined secret correspondence algorithm, the method to be used for the decrypting the data field among a plurality of methods stored in memory. The method of claim 1 wherein, when the time stamp is a timestamp marker by a clock coupled to the application software, there is further provided a step of: f) resetting the internal clock of the read interface from the time marker read in the data field. The method of claim 1 wherein, when the time marker is a sequencing marker, there is further provided, in the event of a message that is compliant following the verifications of step d), a step of: f) updating the sequence number stored in the read interface from the time marker read in the data field. The method of claim 1 wherein it is further provided, in the event of a message confirmed conforming to the verifications of step d), a step of: f) Disabling, if present, a previous prior user authorization stored in the read interface. The method of claim 1 wherein step a) is performed within a remote server integrating the application software. The method of claim 1 wherein the communication device is a mobile phone, and step a) is performed within the communication device by an internal midlet integrating the application software. The process of claim 1 wherein: the encrypted data field furthermore contains specific access authorization conditions, and step d) further comprises a substep of verifying the compliance of the specific access authorization conditions read in the data field. The method of claim 1 wherein step c) of transmitting the message of the communication device to the read interface is a transmission without galvanic contact by means of the group formed by: transmission of acoustic signals; inductive NFC transmission, especially in peer-to-peer mode ; radio transmission, in particular Bluetooth; transmission of light signals, especially IR; transmission of vibrations by mechanical contact.

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