Bluetooth communication method and system

Abstract

The invention relates to a method of Bluetooth communication implemented between a first electronic device (101) and a second electronic device (102), which is able to transmit a secure message comprising data to be processed by the first electronic device (101), comprising: a step (20) of each of the first and second electronic devices (101, 102) obtaining at least one security key, said at least one security key being involved in the design of a secure tag (20); a step (36) of generating a unique distinctive element of the secure message; and a step (38) of the second electronic device (102) transmitting to the first electronic device (101) said secure message comprising said unique distinctive element and said secure tag, said transmitting step comprising a step (44) of establishing a communication link in Bluetooth advertisement mode between said first and second devices (101, 102).

Description

[Technical field]

[0001] The present invention relates to a method and apparatus for forming a connection between devices using Bluetooth, a short-range technology in wireless communication systems, and more particularly to a method and system for Bluetooth communication implemented between a first electronic device and a second electronic device, which in particular continuously processes data such as event data or notification data. [Background technology]

[0002] Bluetooth is a technical standard for wirelessly connecting various devices in close proximity to exchange data. Bluetooth communication methods can be classified into Basic Rate / Enhanced Data Rate (known by the acronym "BR / EDR") and Low Energy (known by the acronym "LE"). The BR / EDR method is sometimes called Bluetooth Classic. Bluetooth Classic methods include Bluetooth technology represented by Bluetooth 1.0 and Bluetooth technology using Enhanced Data Rate (known by the acronym "EDR") supported by Bluetooth 2.0 or later versions.

[0003] Bluetooth Low Energy (known by the acronym "LE") technology, which will be applied starting with Bluetooth 4.0, can reliably provide hundreds of kilobytes (KB) of information with low power consumption. Such Bluetooth Low Energy technology allows devices to exchange information between each other using an attribute protocol. The Bluetooth LE approach can reduce energy consumption by reducing header overhead and simplifying operation.

[0004] In the prior art, it is known to implement a method of Bluetooth communication in a tire pressure monitoring system (known by the acronym "TPMS") to monitor phenomena data related to physical quantities, such as tire pressure measurements. In this type of system, each tire contains a small embedded electronic device, such as a TPMS sensor. This TPMS sensor is configured to communicate with the vehicle's electronic control unit (known by the acronym "ECU") and, during the transmission step of the method, transmits tire pressure measurements to the ECU via an operating mode of the Bluetooth standard, referred to as advertising mode.

[0005] However, one of the drawbacks of such an approach is that the insecure transmission of these tire pressure measurements makes the TPMS system highly vulnerable, as it exposes it to all kinds of malicious attacks.

[0006] To overcome this drawback, state-of-the-art solutions provide for transmitting this tire pressure measurement to the ECU during a transmission step of this method implementing a secure operating mode of the Bluetooth standard called connected mode. Nevertheless, this connected mode generates high power consumption, especially in this type of use, making it unsuitable for small embedded devices such as this TPMS sensor, which require very low power consumption.

[0007] It can therefore be appreciated that there is a need to find alternative solutions, particularly those that do not suffer from the shortcomings of the prior art. Summary of the Invention

[0008] In this context, embodiments of the present disclosure provide methods and systems for Bluetooth communication implemented between a first device and a second device to ensure the integrity, authenticity and / or confidentiality of messages transmitted using the Bluetooth communication protocol primarily or exclusively in advertising mode.

[0009] Furthermore, embodiments of the present disclosure provide complete protection against replay attacks in advertising mode.

[0010] To this end, the invention relates to a method of Bluetooth communication implemented between a first electronic device and a second electronic device, the second electronic device being capable of transmitting secure messages containing data to be processed by the first electronic device, the method comprising the steps of: - each of the first electronic device and the second electronic device obtaining at least one security key, the at least one security key being involved in the design of a secure tag; generating a unique signature for the secure message; sending by the second electronic device to the first electronic device a secure message including the unique singular element and the secure tag; wherein the transmitting step includes establishing a communication link between the first device and the second device in a Bluetooth advertising mode.

[0011] In another embodiment, the generating step includes the sub-step of determining unique singular elements by implementing a unique singular element algorithm; A unique singular element algorithm is a sequence number algorithm if the unique singular element is a sequence number, The unique singular element algorithm is a time stamp number algorithm when the unique singular element is a time stamp number, the obtaining step comprises a sub-step of establishing a communication link in Bluetooth connection mode between the first device and the second device, which sub-step comprises a phase of pairing the first device with the second device and a sub-step of exchanging said at least one security key between said first device and said second device, said at least one security key being initially stored in the first device or in the second device; the obtaining step comprises the sub-step of establishing a communication link in Bluetooth connection mode between the first device and the second device, the sub-step comprising a phase of pairing the first device with the second device and a sub-step of exchanging said at least one security key between said first device and said second device, said at least one security key being a key generated during the pairing phase, the obtaining step comprises the sub-step of establishing a communication link in Bluetooth connection mode between the first device and the second device, the sub-step comprising a phase of pairing the first device with the second device and a sub-step of exchanging said at least one security key between said first device and said second device, said at least one security key being derived from said generated key, the obtaining step includes the sub-steps of establishing a communication link between the first device and the second device in a Bluetooth connection mode, and generating the at least one security key by the first device and the second device by implementing a key agreement protocol; the obtaining step includes the sub-steps of establishing a communication link between the first device and the second device from a wired technology or a wireless technology standard different from the Bluetooth standard, and generating the at least one security key by the first device and the second device by implementing a key agreement protocol; The obtaining step includes the sub-steps of establishing a communication link between the first device and the second device through a wired technology or a wireless technology standard different from the Bluetooth standard, and exchanging the at least one security key between the first device and the second device, the at least one security key being initially stored in the first device or the second device; the obtaining step comprises the sub-steps of establishing a communication link between the first device and the second device from a wired technology or a wireless technology standard different from the Bluetooth standard, and exchanging said at least one security key between said first device and second device, said at least one security key being a key generated during a pairing phase if the obtaining step comprises a previous pairing phase implemented between the first device and the second device, the obtaining step includes the sub-steps of establishing a communication link between the first device and the second device using a wired technology or a wireless technology standard different from the Bluetooth standard, and exchanging the at least one security key between the first device and the second device, the at least one security key being derived from a generated key; the obtaining step includes the sub-steps of establishing a communication link in a Bluetooth connection mode between the first device, the second device and the second device, including a phase of pairing a third device with the first electronic device and the second electronic device, and exchanging the at least one security key over the communication link between the first device and the second device via the third electronic device, the obtaining step includes the sub-steps of establishing a communication link between the first device, the second device and the third device from a selection of communication technologies, the communication technologies being performed by each of these devices in a secure wired technology, or a secure wireless technology different from Bluetooth technology, or Bluetooth technology; and exchanging the at least one security key over the communication links between the first device and the second device via the third electronic device; the sub-step of exchanging is replaced by a sub-step of distributing the at least one security key by the third electronic device to the first device and the second device via a communication link; the step of sending includes the sub-step of realizing a message including a payload including data related to the event data or the notification data; the step of sending includes the sub-step of designing a secure message by using the at least one security key and a payload; the designing sub-step includes a phase of computing a secure tag by implementing a tag algorithm using said at least one security key and a payload, the designing sub-step comprises a phase of computing a secure tag by implementing a tag algorithm using said at least one security key, a payload and a unique element, The designing sub-step includes a phase of generating a secure message by appending a calculated secure tag to a payload and a unique singular element to this payload; The designing sub-step includes a phase of generating a secure message by appending a calculated tag to the encrypted payload and a unique singular element to the encrypted payload, The method includes processing usable data included in a secure message received by a first device from a second device; The step of processing includes the sub-step of extracting a unique signature element included in the available data of the received secure message; The processing step includes the sub-step of extracting a payload contained in the received secure message; The extraction sub-step includes a phase of verifying the consistency of this unique singular element extracted from those available data, the processing step includes the sub-step of generating useful information based on data contained in the payload of the secure message; The secure message, a unique singular element, is contained and / or encrypted in the secure tag.

[0012] The invention also relates to a system of Bluetooth communication implemented between a first electronic device and a second electronic device, the second electronic device being capable of transmitting secure messages including data to be processed by the first electronic device, the system (100) comprising said first electronic device and said second electronic device, - each of the first electronic device and the second electronic device obtaining at least one security key, the at least one security key being involved in the design of a secure tag; generating a unique signature for the secure message; sending by the second electronic device to the first electronic device a secure message including the unique singular element and the secure tag; the transmitting step includes establishing a communication link between the first device and the second device in a Bluetooth advertising mode.

[0013] Advantageously, the system comprises a first electronic device and a second electronic device, and further a third electronic device, the system comprising: exchanging the at least one security key over a communications link between the first electronic device and the second electronic device via a third electronic device; or · distributing, by the third electronic device, the at least one security key to the first electronic device and the second electronic device via a communication link. [Brief description of the drawings]

[0014] The invention will now be described in detail with reference to the accompanying drawings, which are given by way of example and not by way of limitation, in which:

[0015] [Figure 1] 1 is a schematic diagram of a system for Bluetooth communication implemented between a first electronic device and a second electronic device according to the present invention; [Diagram 2]FIG. 2 is a schematic diagram of a variant of a system for Bluetooth communication implemented between a first electronic device, a second electronic device and a third electronic device according to the present invention. [Diagram 3] 1 is a schematic diagram of a Bluetooth communication method according to the present invention; [Figure 4] 4 is a flow chart illustrating a first embodiment of the step of obtaining at least one security key of this method according to the invention. [Diagram 5] 4 is a flow chart illustrating a second embodiment of the obtaining step of this method according to the invention. [Figure 6] 5 is a flow chart illustrating a third embodiment of the obtaining step of this method according to the present invention. [Figure 7] 6 is a flow chart illustrating a fourth embodiment of the obtaining step of this method according to the invention. [Figure 8] 8 and 9 are flow charts illustrating two alternatives of a fifth embodiment of the obtaining step of this method according to the invention. [Figure 9] 8 and 9 are flow charts illustrating two alternatives of a fifth embodiment of the obtaining step of this method according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] In different embodiments of the invention shown in figures 1 and 2, a method and system 100 for short-range wireless communication, in particular a Bluetooth communication method and system 100, is disclosed for providing and managing the exchange of messages between a first electronic device 101 and a second electronic device 102. In particular, these methods and systems 100 contribute to realizing the exchange of messages between these two electronic devices 101, 102 in an operating mode of the Bluetooth standard called advertising mode. In particular, the Bluetooth communication method and system 100 allows the second device 102 to advertise these messages to the first device 101 in a secure manner.

[0017] This Bluetooth advertising mode, referred to as A in Figures 4 to 9, is now a different mode for establishing Bluetooth communication, i.e., by non-connectable omnidirectional advertising. The difference between the two-device connection mode, referred to as C in Figures 4 to 9, and the advertising mode is that the connection mode allows two-way data transfer between the two devices. On the other hand, a device in advertising mode cannot receive data in that state. One exception is that an advertising device can respond to a "scan request" packet.

[0018] In this context, the advertised messages are secure messages whose integrity, authenticity and / or confidentiality are guaranteed by these Bluetooth communication methods and systems 100. Such secure messages contain usable data, preferably including a payload, a secure tag and a unique element that is unique for each message. As will be explained later, this unique unique element may be, non-limitingly and / or non-exhaustively, a sequence number or a timestamp. In an embodiment of the present invention, for each secure message exchanged between the first electronic device 101 and the second electronic device 102, a new unique unique element is generated.

[0019] In this secure message, the payload contains useful data that can be continuously processed or continuously monitored. Continuously here means periodic or without interruption. This useful data can for example be phenomenal data, also called event data. These phenomenal data can contain physical and / or biological values. Such values ​​relate to physical or biological quantities. As can be understood, physical quantities are included in the field of physical sciences and biological quantities in the field of life sciences (also called "biology"). These values ​​are calculated by the second device 102 from measurements of physical and / or biological quantities evaluated by at least one data generator of this device 102.

[0020] Additionally, these useful data may be notification data, which includes alphanumeric characters related to communication of information, which may include alert communication, news communication, event communication, and the like.

[0021] In the system 100, the first electronic device 101 may be, without limitation and / or without limitation, a vehicle electronic control unit, an internet server, a router, a desktop or laptop computer, a smartphone, a tablet, a processor, a module, etc., and may be implemented in various forms including, for example, an integrated circuit or collection thereof, a printed circuit board or collection thereof, or in a separate housing / package / rack or a combination thereof.

[0022] This first device 101 may include, but is not limited to, and / or non-exhaustively, a processing unit 104 (also called "controller") including hardware and software resources, in particular at least one processor 111 cooperating with a memory element 112; A Bluetooth communication interface 109; A wired and wireless communication interface 110 that is not compatible with the Bluetooth standard; Includes.

[0023] In this configuration, the processing unit 104 is connected to a Bluetooth communication interface 109, and the wired and wireless communication interface 110 is not compatible with the Bluetooth standard.

[0024] This first device 101 may also include an interface 107 for broadcasting visual information, such as a digital display, an interface 108 for broadcasting audio information, such as a loudspeaker, and an input interface 106, e.g. a touch interface included in the interface for broadcasting visual information.

[0025] In addition, the first device 101 may be configured to receive signals from one or more second devices 102, process the received signals, and control the one or more second devices 102 via control signals.

[0026] The second device 102 may include, but is not limited to, and / or includes, a processing unit 105 (also called "controller") including hardware and software resources, in particular at least one processor 118 cooperating with a memory element 119; A Bluetooth communication interface 114; A wired and wireless communication interface 113 that is not compatible with the Bluetooth standard; At least one data generator 120; a data generator circuit 115, which may be referred to as a signal processing circuit 116 and / or a signal conditioning circuit 117, which receives this electrical signal from at least one data generator 120 in the form of raw measurement data; Includes.

[0027] In this second device 102 , a processing unit 105 is connected to a Bluetooth communication interface 114 , a wired and wireless communication interface 113 not compatible with the Bluetooth standard, and a data generator circuit 115 connected to at least one data generator 120 .

[0028] In this configuration, the data generator 120 is preferably a sensor. This sensor is an element capable of converting a physical or biological quantity to be measured into an electrical signal (also called "sensor signal"). Such a physical quantity can be, for example, the tire pressure of a vehicle in the context of a tire pressure monitoring system (known by the acronym "TPMS"), or the monitoring of atmospheric pressure and temperature for a weather forecasting system, etc. As for biological quantities, it can be, for example, the heart rate and blood pressure monitored in the context of an electrocardiogram system. Sensors can also measure insulin rates, brain signals, etc. Other applications can be in agricultural fields where the moisture content, chemical properties of the soil are measured. Other sensors are present in fire and safety areas. Sensors detect the presence of radioactivity, gases such as carbon monoxide, nanoparticles, etc.

[0029] Alternatively, the data generator 120 may be a wireless communication device such as a transponder for wirelessly unlocking a vehicle, e.g., a car key fob. In the consumer area, connected wearables such as connected watches are typical examples of devices that receive notifications, calls, messages, and other data generated by smartphones.

[0030] In this second device 102, the data generator circuit 115 may include an analog-to-digital converter (known by the acronym "ADC") that converts an analog signal from a value related to a physical or biological quantity to a digital signal. The data generator circuit may also include a digital signal processor (known by the acronym "DSP") that performs some processing on the digital signal (e.g., to prepare the value of the physical or biological quantity for transmission). Thus, the data generator package includes circuitry to condition and amplify small signals of this value by signal processing and / or conditioning. Signal conditioning, as used herein, refers to manipulating an analog signal in such a way that the signal meets the requirements of the next stage for further processing. Signal conditioning may include analog-to-digital conversion (e.g., via an analog-to-digital converter), amplification, filtering, conversion, biasing, range matching, separation, and any other process necessary to make the data generator output suitable for conditioned processing.

[0031] In the first device 101 and the second device 102, the processing units 104, 105 may implement tag algorithms, unique signature algorithms, encryption algorithms such as the Diffie-Hellman algorithm, and / or encryption algorithms such as the Advanced Encryption Standard (known by the acronym "AES") and corresponding decryption algorithms, which are stored in their memory elements 112, 119. In this context, these tag algorithms may be, for example, a MAC algorithm, such as the Advanced Encryption Standard Cipher-based Message Authentication Code Algorithm (known by the acronym "AES-CMAC") or the Hash-based Message Authentication Code Algorithm (known by the acronym "HMAC"), for calculating this tag based on the at least one security key and the payload, or A signature algorithm, such as the Elliptic Curve Digital Signature Algorithm (known by the acronym "ECDSA"), for calculating this tag based on said at least one security key and a payload.

[0032] In this context, the unique unique element algorithm includes a sequence number algorithm, in case the unique unique element is a sequence number. This sequence number algorithm may be a counter or a timestamp. The unique unique element algorithm is responsible for generating unique unique elements that are different from each other, i.e., these identifying elements will never be the same. In other words, throughout the life of these first and second devices, these unique identifying elements will always be different. This particular feature ensures that each secure message can be used / sent / exchanged only once.

[0033] It should be noted that the system 100 includes a communication network 121 involved in establishing a communication link between the first device 101 and the second device 102. This communication network 121 is preferably a Bluetooth communication network or a non-Bluetooth compatible wired and wireless communication network.

[0034] The system 100 may further include a third electronic device 103 that may participate in the exchange of at least one security key between the first device 101 and the second device 102 and distribute the at least one security key to the first device 101 and the second device 102.

[0035] This device 103 may be present, for example, in a TPMS system or other similar system.

[0036] The third device 103 may include, but is not limited to, and / or non-exhaustively, a processing unit 122 (also called "controller") including hardware and software resources, in particular at least one processor 125 cooperating with a memory element 126; A Bluetooth communication interface 123; - Wired and / or wireless communication interfaces that are not compatible with Bluetooth Standard 124 Includes.

[0037] In this third device 103, a processing unit 122 is connected to a Bluetooth communication interface 123 and further to a wired and wireless communication interface 124 which, as previously mentioned, is not compatible with the Bluetooth standard.

[0038] According to some embodiments, the first device 101, the second device 102 or the third device 103 may include in a memory element 112, 119, 126 of its processing unit 104, 105, 122 the at least one security key for protecting messages.

[0039] Furthermore, the system 100 includes two communication networks 127, 128 involved in establishing the communication links between the third device 103 and the first device 101, and between the third device 103 and the second device 102, respectively. These communication networks 127, 128 are preferably Bluetooth communication networks or non-Bluetooth compatible wired and wireless communication networks.

[0040] 3 to 9, a system 100 can implement this Bluetooth communication method, which includes a step 18 in which each of the first device 101 and the second device 102 obtains said at least one security key. Such obtaining step 18 preferably includes five embodiments:

[0041] More specifically, in the first and second embodiments illustrated in figures 4 and 5, this step 18 comprises a sub-step 19 of establishing a communication link in Bluetooth connection mode between the first device 101 and the second device 102. To that end, this sub-step 19 comprises a phase 20 of pairing the first device 101 with the second device 102.

[0042] In this context, the Bluetooth connection mode, referred to as C in Figures 4 to 9, may be defined as a connection that allows bidirectional data transfer between two connected devices. In the connection mode, the data transferred may be, but is not necessarily, protected. The data transferred may be protected in terms of integrity or confidentiality.

[0043] This sub-step 19 is implemented automatically only when the first device 101 receives a connection request from a second device 102 with which it has not yet been paired. During this sub-step 19, the first device 101 detects the presence of the second device 102 in its vicinity and tries to establish a connection with this last device. To this end, the second device 102 is set in discoverable mode. Then, during this pairing phase 20, the first device 101 or the second device 102, specifically its processing unit 104, 105, can generate several keys, such as, for example, a Long Temporary Key, an Identity Resolving Key, a Connection Signature Resolving Key and / or a Diffie-Hellman key.

[0044] In a first embodiment, the obtaining step 18 includes a sub-step 21 of exchanging the at least one security key between the first device 102 and the second device. This sub-step 21 includes: Phase 22, in which the first device 101 transmits the at least one security key to the second device 102; or Phase 23, in which the second device 102 sends the at least one security key to the first device 101.

[0045] In this context, the at least one security key may be a key already stored in the processing unit 104, 105 of the first device 101 or the second device 102, such as an Advanced Encryption Standard key. In one alternative, the at least one security key may be a key generated during the pairing phase 20, or a key derived from a key generated.

[0046] In a second embodiment, the obtaining step 18 includes a sub-step 24 in which the first device 101 and the second device 102 generate said at least one security key by implementing a key agreement protocol, which may be based on a cryptographic algorithm such as, for example, the Diffie-Hellman algorithm.

[0047] With reference to figure 6, for a third embodiment of this obtaining step 18 similar to the second embodiment, it is foreseen that the sub-step 19 of establishing communication is replaced by a sub-step 25 of establishing a communication link between the first device 101 and the second device 102 from a wired or wireless technology standard different from the Bluetooth standard. After this sub-step 25, this third embodiment includes, as in this second embodiment, a sub-step 26 in which the first device 101 and the second device 102 generate said at least one security key by implementing a key agreement protocol.

[0048] In the fourth embodiment shown in Fig. 7, the obtaining step 18 also includes a sub-step 27 of establishing a communication link between the first device 101 and the second device 102 from a wired or wireless technology standard different from the Bluetooth standard, as in the third embodiment. The obtaining step 18 then includes a sub-step 28 of exchanging said at least one security key between said first device 101 and second device 102, said at least one security key being: Initially stored in the first device 101 or the second device 102, or if the obtaining step 18 comprises a previous pairing phase implemented between the first device 101 and the second device 102, the keys generated during that pairing phase, or · It is derived from the generated key.

[0049] In a fifth embodiment of the obtaining step 18 depicted in FIGS. 8 and 9, this step 18 comprises: a substep 29 of establishing a communication link in Bluetooth connection mode between the first device 101, the second device 102 and the third device 103, the substep 29 including a phase of pairing the third device 103 with the first electronic device 101 and the second electronic device 102, or a sub-step 30 of establishing a communication link between the first device 101, the second device 102 and the third device 103 from a selection of a communication technology, the communication technology being performed by each of these devices 101, 102, 103 in a secure wired technology, or a secure wireless technology different from Bluetooth technology, or in Bluetooth technology.

[0050] In this fifth embodiment, the obtaining step 18 then comprises: substep 31 of exchanging said at least one security key over a communication link between the first device 101 and the second device 102 via a third electronic device 103; or The third electronic device 103 distributes the at least one security key to the first device 101 and the second device 102 via a communication link.

[0051] Substep 31 to replace a phase 33 of transmitting said at least one security key from the first device 101 to the second device 102 via the third device 103; or A phase 34 of transmitting the at least one security key from the second device 102 to the first device 101 via the third device 103.

[0052] In this context, the at least one security key may be a key already stored in the processing unit 104, 105, 122 of the first device 101, the second device 102 or the third device 103, such as for example an Advanced Encryption Standard key. In an alternative, the at least one security key may also be a key generated during the pairing phase 22 of this fifth embodiment, or a key derived from a key generated during this phase. Note that during this phase the first device 101, the second device 102 or the third device 103, in particular its processing unit 104, 105, 122, may generate several keys, such as for example a long temporary key, an identity resolution key, a connection signature resolution key and / or a Diffie-Hellman key.

[0053] The method then includes a step 35 of interrupting the communication link between the first device 101 and the second device 102 as long as the at least one security key is valid. Note that the communication link between the first device 101 and the second device 102 is interrupted directly if the two devices 101, 102 are connected to each other without an intermediate device as in the first to fourth embodiments described above. In the same approach, the communication link between the first device 101 and the second device 102 is interrupted indirectly if the two devices 101, 102 are connected to each other via a third device 103 as in the fifth embodiment described above.

[0054] It will be appreciated that the at least one security key is considered valid once the two devices 101 and 102 agree on the key material, which may be either a shared secret key or a private / public key pair.

[0055] That is, once the at least one security key is valid, in the method, the sub-steps 19, 25, 27, 29, 30 of establishing a communication link between the first device 101 and the second device 102 or between the first device 101, the second device 102 and the third device 103 are In Bluetooth connection mode, or There is no need to implement a secure wired technology or a secure wireless technology other than Bluetooth technology.

[0056] Furthermore, the method comprises a step 36 of generating a unique distinctive element for / for the secure messages. This unique distinctive element is generated in particular for each secure message exchanged between the first device 101 and the second electronic device 102. In other words, a new and / or different unique distinctive element is generated for each of these secure messages compared to the previous unique distinctive element. The processing unit 105 of the second device 102 implements this step 36.

[0057] This generating step 36 includes a sub-step 37 of determining a unique singular element by implementing a unique singular element algorithm. During this sub-step 37, the at least one processor 118 of the second device 102 executes this unique singular element algorithm stored in its memory element 119. As mentioned above, the unique singular element algorithm may be a sequence number algorithm in case the unique singular element is a sequence number.

[0058] It should be noted that although this generating step 36 may be implemented at any time in the method, it is essential that it is implemented before a step 38 in which the second device 102 transmits a secure message to the first device 101, as described below.

[0059] Furthermore, the method includes a step 38 of sending a secure message by the second device 102 to the first device 101. Such step 38 includes a sub-step 39 of realizing a message including a payload including data related to the event data or notification data.

[0060] This step 38 then includes a sub-step 40 of designing a secure message by using said at least one security key, payload or unique element. To do so, the sub-step 40 comprises: a phase (41) of computing a secure tag by implementing a tag algorithm using said at least one security key and said payload, and · A phase (41) of computing a secure tag by implementing a tag algorithm using said at least one security key and said payload.

[0061] This secure tag is a short piece of information that contributes to guarantee the integrity and / or authenticity protection of the message containing the payload. This secure tag includes a Message Integrity Code (known under the acronym MIC) or a Message Authentication Code also called a signature (known under the acronym MAC). During this phase 41, the processing unit 105 of the second device 102 can execute this tag algorithm (for example a MAC algorithm or a signature algorithm), which implements the at least one security key and the payload to calculate this secure tag.

[0062] This sub-step 40 then converts the calculated secure tag and unique singular element into Payload, or an encrypted payload (if this designing substep 40 includes a phase 43 of encrypting the payload from an encryption algorithm using said at least one security key); The method includes a phase 42 of generating a secure message by appending

[0063] It should be noted that in addition to the payload, the secure tag and / or the unique singular element may also be encrypted during this encryption phase 43. For example, in this context, a first security key may be used to calculate the security tag and a second security key may be used to encrypt the payload, the unique singular element and / or the tag.

[0064] If this encryption phase 43 is performed, the processing unit 105 of the second device 102 may implement this encryption algorithm to encrypt this payload by using said at least one security key, such phase 43 contributing to guarantee confidentiality of the message including the payload.

[0065] As a note, it is understood that in a secure message, the same / unique security key is involved in encrypting the secure tag and / or the payload and / or the unique singular element. As an alternative in a secure message, different security keys may contribute to the encryption of the secure tag, the payload and / or the unique singular element.

[0066] Thus, in this context, a secure message refers, without limitation and / or without exhaustively, to: The payload, secure tag, and unique singular element, or The payload, the encrypted secure tag, and the unique singular element, or The payload, secure tag, and encrypted unique singular element, or the payload, the encrypted secure tag, and the encrypted unique singular element, or Encrypted payload, secure tag, and unique singular element, or - an encrypted payload, an encrypted secure tag, and a unique singular element; or An encrypted payload, a secure tag, and an encrypted unique singular element, or an encrypted payload, an encrypted secure tag, and an encrypted unique singular element; or a secure tag computed by the payload, a unique singular element, and a unique singular element; or a payload, an encrypted secure tag calculated by a unique singular element, and a unique singular element; or a secure tag computed by the payload, a unique singular element, and an encrypted unique singular element; or a payload, an encrypted secure tag computed by a unique singular element, and an encrypted unique singular element; or a secure tag calculated from the encrypted payload, the unique singular element, and the unique singular element; or an encrypted payload, an encrypted secure tag computed by a unique singular element, and a unique singular element; or a secure tag computed by the encrypted payload, the unique singular element, and the encrypted unique singular element; or · It may contain usable data including an encrypted payload, an encrypted secure tag calculated by the unique singular element, and an encrypted unique singular element.

[0067] In addition, it will be appreciated that in this secure message the unique singular element is preferably included in the computation of the secure tag and / or encrypted.

[0068] Once the secure message has been constructed, the sending step 38 results in the implementation of a sub-step 44 of establishing a communication link in Bluetooth advertising mode between the first device 101 and the second device 102. The sending step 38 then includes a sub-step 45 of the second device 102 advertising the secure message to the first device 101.

[0069] The method then comprises a step 46 of processing the usable data contained in the secure message received by the first device 101 from the second device 102. Step 46 comprises a sub-step 47 of extracting a unique singular element contained in the usable data of the received secure message.

[0070] In particular, this sub-step 47 includes a phase 48 of verifying the consistency of the unique singular elements extracted from the available data.

[0071] Such consistency is verified by comparing the received unique element with a calculated unique element obtained by the first device by implementing a unique unique element algorithm (e.g. a sequence number algorithm if the unique unique element is a sequence number, or a timestamp number algorithm if the unique unique element is a timestamp number).

[0072] In this context, the sequence number algorithm may for example be implemented as a counter, which is incremented from an increment factor (e.g. an increment value) to obtain a calculated unique element (i.e. a calculated sequence number). The algorithm executed by the processing unit 104 of the first device 101 is then responsible for controlling whether the calculated unique element is equal or slightly equal to the received unique element (i.e. the received sequence number), which has also been incremented from the same increment factor during the generation of this secure message.

[0073] Regarding the time stamp number algorithm, it is also possible to implement, for example, the evaluation of the difference between the received and calculated singular elements, where these two singular elements are: a processing unit 104 of the first device 101 for determining the calculated singular elements, A processing unit 105 of the second device 102 for determining the received distinctive element contained in the usable data of the secure message The date information fetched by this algorithm may be: This algorithm, executed by the processing unit 104 of the first device 101, is then responsible for controlling whether the evaluated difference between the calculated distinctive element and the received distinctive element is less than, more than or equal to the reference / reported difference stored in this processing unit 104.

[0074] Such consistency is also verified by comparing the unique element of the received secure message with the unique element contained in the preceding secure message. In this context, a unique element algorithm is executed by the processing unit 104 of the first device 101 to fetch the unique element of a previous secure message stored in this processing unit 104 and to control whether this previous unique element is similar to the new unique element of the last received secure message. In one alternative, this unique element algorithm executed by the processing unit 104 may also contribute to controlling whether the new unique element is less / more / equal to this previous secure element. It should be noted that for a first secure message advertised / sent by the second device to the first device, the unique element contained in this secure message and the unique element stored in the processing unit 104 of the first device 101 are initialized to the same value or the same alphanumeric character. Such unique element stored in the processing unit 104 is intended to be compared with the unique element contained in this first secure message.

[0075] Such consistency is also verified by comparing the received unique element with a unique element from the plurality of unique elements stored in the processing unit 104 of the first device 101. In this context, a unique element algorithm is executed by the processing unit 104 of the first device 101 to find in said processing unit 104 a unique element corresponding to said received unique element. However, the same plurality of unique elements is stored in the processing unit 104 of the first device 101 and in the processing unit 105 of the second device 102, in which each unique element is different from the other unique elements of said plurality. It should be noted that the unique element, which is the usable data of the secure message, is randomly selected from the plurality of unique elements stored in the processing unit 105 of the second device 102 by the unique element algorithm executed by said processing unit 105 of said processing unit 105.

[0076] If the consistency of the unique singular element contained in the usable data of the secure message is verified, the processing unit 104 of the first device 101 can safely assume that the secure message was indeed received by this first device 101 for the first time and has not been replayed.

[0077] It should be noted that if the designing sub-step 40 comprises a phase 43 of encrypting this unique singular element, the verifying phase 48 may comprise a sub-phase of decrypting the encrypted unique singular element contained in the received secure message. During this decrypting phase 50, the processing unit 104 of the first device 101 may implement a corresponding decryption algorithm to decrypt this encrypted unique singular element by using said at least one security key. In this way, confidentiality protection of the unique singular element is guaranteed.

[0078] In this context, the processing step 46 comprises a sub-step 49 of extracting the payload contained in the received secure message once the consistency of the unique singular element contained in the usable data of the secure message has been verified.

[0079] As mentioned above, the processing step 46 comprises a sub-step 49 of extracting the payload contained in the received secure message. Sub-step 49 comprises a phase 50 of processing the consistency of the secure tag contained in the secure message. This consistency is verified either by comparing the calculated tag with the received tag or by verifying the validity of the received signature tag. If the received tag in the secure message is valid, the processing unit 104 of the first device 101 may safely assume that the message has not been modified or tampered with during transmission. In other words, the integrity and / or authenticity of this message, in particular of the payload, may be considered as unmodified.

[0080] Sub-step 49 then comprises a phase 51 of verifying the consistency of the tag contained in the secure message. If the tag is consistent, the processing unit 104 of the first device 101 can safely assume that the message has not been modified or tampered with during transmission. In other words, the integrity and / or authenticity of this message, and in particular of its payload, can be considered as unmodified.

[0081] If the designing sub-step 40 includes a phase of encrypting a payload, the sub-step 49 may include a phase 52 of decrypting the encrypted payload contained in the received secure message.

[0082] During this decryption phase 52, the processing unit 104 of the first device 101 may implement a corresponding decryption algorithm to decrypt this encrypted payload by using said at least one security key. In this way, confidentiality protection of the message, and in particular of the payload, is guaranteed. In this sub-step 49, this phase 52 is performed before the phase 50 of processing the integrity of the secure tag, which requires the decrypted payload to be implemented.

[0083] In other words, if the secure tag and / or payload contained in the received secure message have been encrypted during the designing substep 40, the decrypting phase 52 may be performed before the processing of the secure tag phase 50.

[0084] The processing step 46 then includes a sub-step 53 of generating useful information based on the data contained in the payload of this secure message, which can be used in a biological or physical parameter monitoring system, such as a TPMS system.

[0085] It can therefore be seen that the invention offers the advantage of allowing these first and second devices to exchange messages securely in Bluetooth advertising mode, while also guaranteeing the freshness of these secure messages by using a unique distinctive element, thus ensuring complete protection against replay attacks. In this context, the use of a unique distinctive element ensures that each secure message can only be used once.

[0086] Additionally, the present invention ensures the integrity and authenticity of secure messages advertised via Bluetooth technology against malicious modification, and further optimizes the use of one-way versus two-way communication.

[0087] In addition, the present invention -Full protection against replay attacks in advertising mode, Very low power consumption compared to persistent connection mode, protected against replay attacks; Greener devices 101, 102 due to a longer device lifespan due to a dramatic reduction in power consumption compared to the persistent connection mode where similar concepts have been previously implemented; Reduced complexity of the devices 101, 102 due to the possibility of ensuring protection against replay attacks without using a persistent connection mode for most or all of the communication, It should be noted that this provides many advantages, including: less additional effort for the first and second devices (101, 102).

[0088] Additionally, the present invention allows the second device 102 to advertise messages with integrity, authenticity and confidentiality protection. To achieve this, each encrypted message exchanged between the two devices 101, 102 includes a payload and a tag calculated from a key.

[0089] Finally, the present invention may be implemented in all of the following technical fields, without limitation and / or without exhaustive limitation: Automotive (e.g. passenger cars, commercial vehicles, trucks), two-wheelers (e.g. motorcycles, bicycles, e-bikes, scooter applications), three-wheelers (e.g. electric three-wheelers): tire pressure monitoring sensors (TPMS) advertising via Bluetooth, e-call communicating with smartphones via Bluetooth, presence detectors (e.g. baby seats) communicating with smartphones via Bluetooth, e-bike sensors and devices communicating with receivers via Bluetooth, Medical: Communication for portable medical devices such as pacemakers and hearing aids that communicate data to a receiver via Bluetooth; Agriculture: Sensors on farms communicating data via Bluetooth to a gateway; Industrial: Sensors integrated into production tools that communicate data to a gateway via Bluetooth, asset tracking, Consumer market: Numerous applications for Bluetooth communication between smartphones, tablets, laptops and wearables, hearables and gaming toys.

[0090] As will be apparent to those skilled in the art, various modifications can be made in the present disclosure without departing from the spirit or scope of the present disclosure. Accordingly, it is intended that the present disclosure include modifications and variations of the embodiments of the present disclosure.

Claims

1. A method of Bluetooth communication implemented between a first electronic device (101) and a second electronic device (102), the second electronic device (102) being capable of sending secure messages including data to be processed by said first electronic device (101), The method comprises: - a step (20) of obtaining at least one security key for each of the first and second electronic devices (101, 102), said at least one security key being involved in the design of a secure tag; - generating (36) a unique signature element for said secure message; - sending (38) by the second electronic device (102) to the first electronic device (101) the secure message containing the unique singular element and this secure tag; Including, The method, wherein the transmitting step includes a step (44) of establishing a communication link between the first and second devices (101, 102) in a Bluetooth advertising mode.

2. 2. The method of claim 1, wherein the generating step (36) includes a substep (37) of determining the unique singular elements by implementing a unique singular element algorithm.

3. said unique singular element algorithm comprising: a sequence number algorithm if the unique singular element is a sequence number; or A time stamp number algorithm if the unique singular element is a time stamp number.

3. The method according to claim 1 .

4. The obtaining step (20) a substep (19) of establishing a communication link between said first and second devices (101, 102) in Bluetooth connection mode, said substep (19) including a phase (22) of pairing said first device (101) with said second device (102); a substep (23) of exchanging said at least one security key between said first and second devices (101, 102); Including, The at least one security key is initially stored in said first or second device (101, 102); or a key generated during the pairing phase (22), or Derived from that generated key 4. The method according to claim 1, wherein the

5. The obtaining step (20) - a substep (19) of establishing a communication link between said first and second devices (101, 102) in Bluetooth connection mode; - generating (26) said at least one security key by said first and second devices (101, 102) by implementing a key agreement protocol; 4. The method according to claim 1, further comprising:

6. The obtaining step (20) - a substep (27) of establishing a communication link between said first and second devices (101, 102) via a wired technology or a wireless technology standard different from the Bluetooth standard; - generating (28) said at least one security key by said first and second devices (101, 102) by implementing a key agreement protocol; 4. The method according to claim 1, further comprising:

7. The obtaining step (20) - a substep (29) of establishing a communication link between said first and second devices (101, 102) via a wired technology or a wireless technology standard different from the Bluetooth standard; a substep (30) of exchanging said at least one security key between said first and second devices (101, 102); Including, The at least one security key is initially stored in said first or second device (101, 102); or If the obtaining step includes a previous pairing phase implemented between the first and second devices (101, 102), the keys generated during that pairing phase, or Derived from that generated key 4. The method according to claim 1, wherein the

8. The obtaining step (20) a substep (31) of establishing a communication link in Bluetooth connection mode between a first device, a second device and a third device (101, 102, 103), the substep (31) including a phase of pairing the third device (103) with said first electronic device (101) and said second electronic device (102); - exchanging (33) said at least one security key over said communication link between said first and second devices (101, 102) via said third electronic device (103); 4. The method according to claim 1, further comprising:

9. The step of obtaining includes: - a sub-step (32) of establishing a communication link between the first device, the second device and the third device (101, 102, 103) from a selection of a communication technology, said communication technology being performed by each of said devices (101, 102, 103) in a secure wired technology, or a secure wireless technology different from Bluetooth technology, or in Bluetooth technology; - exchanging (33) said at least one security key over said communication link between said first and second devices (101, 102) via said third electronic device (103); 4. The method according to claim 1, further comprising:

10. 10. The method according to claim 8 or 9, characterized in that the substep (33) of exchanging is replaced by a substep (34) of the third electronic device (103) distributing the at least one security key to the first and second devices (101, 102) via the communication link.

11. The transmitting step (38) - realizing (39) a message including a payload containing data related to the event data or notification data; - designing (40) said secure message by using said at least one security key and said payload; 11. The method according to claim 1, comprising:

12. The designing sub-step (40) comprises: - a phase (41) of computing the secure tag by implementing a tag algorithm using the at least one security key and the payload, or - Computing a secure tag by implementing a tag algorithm using said at least one security key and said payload (41).

10. The method according to claim 1, comprising:

13. The designing sub-step (40) comprises: a phase (42) of generating the secure message by appending the computed secure tag to the payload and the unique singular element to this payload, or A phase (42) of generating said secure message by appending said calculated tag to said encrypted payload and said unique singular element to this encrypted payload.

13. The method according to any one of claims 1 to 12, characterized in that it comprises:

14. 14. The method according to any one of claims 1 to 13, characterized in that it comprises a step (46) of processing (46) usable data contained in the secure message received by the first device (101) from the second device (102).

15. The processing step (46) comprises: - extracting (47) said unique singular element contained in the usable data of said received secure message; - extracting (49) the payload contained in the received secure message; 15. The method according to claim 1 , comprising:

16. Method according to any one of claims 1 to 15, characterized in that said extracting substep (47) comprises a phase (48) of verifying the consistency of this unique singular element extracted from those available data.

17. The method according to any one of claims 13 to 16, wherein the processing step (46) comprises a sub-step (53) of generating useful information based on data contained in the payload of the secure message.

18. 18. The method according to any one of claims 1 to 17, characterized in that in this secure message the unique singular element is included in the calculation of the secure tag and / or is encrypted.

19. A Bluetooth communication system (100) implemented between a first electronic device (101) and a second electronic device (102), This second electronic device (102) is capable of sending a secure message containing data to be processed by said first electronic device (101), The system (100) includes the first device and the second device (101, 102), - obtaining at least one security key by each of said first and second electronic devices (101, 102), said at least one security key being involved in the design of a secure tag; - generating a unique signature for the secure message; - transmitting by the second electronic device (102) to the first device (101) said secure message containing its unique signature and said secure tag, comprising a step (44) of establishing a communication link in Bluetooth advertising mode between said first and second devices (101, 102); The system (100) is configured to:

20. The first device and the second device (101, 102), and further a third electronic device (103), The system (100) comprises: - exchanging said at least one security key over a communication link between said first and second devices (101, 102) via said third electronic device (103); or - distributing said at least one security key by said third electronic device (103) to said first and second devices (101, 102) via said communication link; 20. The system (100) of claim 19, configured to:

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