Bluetooth communication method and system

Abstract

The method relates to 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 transmitting a secure message including data to be processed by the first electronic device (101), the method comprising: a step (20) for each of the first electronic device and the second electronic device (101, 102) obtaining at least one security key, a step (38) of the second electronic device (102) transmitting the secure message to the first electronic device (101), the method comprising a step (44) of establishing a communication link in a Bluetooth advertisement mode between the 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 the following:

[0009] 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 second electronic device sending a secure message to the first electronic device; wherein the transmitting step includes establishing a communication link between the first device and the second device in a Bluetooth advertising mode.

[0010] In another embodiment, The steps to obtain - establishing a communication link between a first device and a second device in a Bluetooth connection mode, the sub-step including a phase (22) of pairing the first device with the second device; * exchanging said at least one security key between said first and second devices. and and the at least one security key comprises: - initially stored on the first device or the second device; or - a key generated during the pairing phase, or - Derived from the generated key. The steps to obtain establishing a communication link between the first device and the second device in a Bluetooth connection mode; generating said at least one security key by said first device and said second device implementing a key agreement protocol; Includes. The steps to obtain establishing a communication link between the first device and the second device via a wired technology or a wireless technology standard different from the Bluetooth standard; generating said at least one security key by said first device and said second device implementing a key agreement protocol; Includes. The steps to obtain establishing a communication link between the first device and the second device via a wired technology or a wireless technology standard different from the Bluetooth standard; exchanging said at least one security key between said first and second devices; and the at least one security key comprises: - initially stored on the first device or the second device; or - if the obtaining step includes a previous pairing phase implemented between the first device and the second device, the key generated during that pairing phase; or - Derived from the generated key. The steps to obtain * a sub-step of establishing a communication link in Bluetooth connection mode between the first device, the second device and the second electronic device, the sub-step including a phase (22) of pairing the third device with the first electronic device and the second electronic device; exchanging said at least one security key over a communications link between the first device and the second device via a third electronic device; Includes. The steps to obtain * establishing a communication link between the first device, the second device and the third device from a selection of a communication technology, the communication technology being performed by each of these devices in a secure wired technology, or a secure wireless technology different from Bluetooth technology, or Bluetooth technology; exchanging said at least one security key over a communications link between the first device and the second device via a third electronic device; Includes. The sub-step of exchanging is replaced by a sub-step of the third electronic device distributing said at least one security key to the first device and the second device via a communication link. The sending step is * realizing a message including a payload including data related to the event data or notification data; designing a secure message by using said at least one security key and a payload; Includes. The sub-steps to design are: - computing a secure tag by implementing a tag algorithm using said at least one security key and a payload; * A phase that generates a secure message by appending the calculated tag to the payload, or * A phase that generates a secure message by appending the calculated tag to the encrypted payload. Includes. * generating a secure message by encrypting the calculated tag appended to the payload; or The method includes processing data included in a secure message received by a first device from a second device; The processing step is * extracting a payload from the received secure message; generating useful information based on data contained in the payload of the secure message; Includes.

[0011] 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 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 second electronic device sending a secure message to the first electronic device; the transmitting step includes establishing a communication link between the first device and the second device in a Bluetooth advertising mode.

[0012] 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 and a third electronic device distributing 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]

[0013] 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:

[0014] [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] 5 is a flow chart illustrating a fifth embodiment of the obtaining step of this method according to the invention. [Figure 9] 5 is a flow chart illustrating a fifth embodiment of the obtaining step of this method according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] 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.

[0016] 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. In the prior art, the advertising mode is not a secure transmission mode.

[0017] In this context, the messages advertised are secure messages whose integrity, authenticity and / or confidentiality are guaranteed by these Bluetooth communication methods and systems 100. Such messages preferably contain a payload containing useful data that can be processed continuously (e.g., periodically).

[0018] The useful data may for example be phenomenon data, also called event data. These phenomenon data may include 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 are included 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 said device 102.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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 .

[0027] 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.

[0028] 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.

[0029] 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.

[0030] In the first device 101 and the second device 102, the processing units 104, 105 Tag algorithms, Encryption algorithms, such as the Diffie-Hellman algorithm, and / or An encryption algorithm, such as the Advanced Encryption Standard (known by the acronym "AES"), and a corresponding decryption algorithm may be implemented, which are stored in their own memory elements 112, 119.

[0031] In this context, these tagging algorithms are e.g. 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] 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.

[0033] 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.

[0034] In this context, the device 103 may be a configuration device and / or a programming device, for example in a TPMS system this device 103 may be a TPMS programming tool in a workshop, a smartphone or a programming device or a TPMS configuration tool on a production line.

[0035] The third device 103 may include, but is not limited to, and / or includes, 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 wireless communication interfaces that are not compatible with Bluetooth standard 124 Includes.

[0036] In this third device 103, the processing unit 122 is connected to a Bluetooth communication interface 123, and the wired and wireless communication interface 124 is not compatible with the Bluetooth standard.

[0037] 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.

[0038] 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.

[0039] 3 to 9, a system 100 can implement this Bluetooth communication method, which starts with step 20 in which each of the first device 101 and the second device 102 obtains the at least one security key. Such obtaining step 20 preferably includes five embodiments:

[0040] More specifically, in the first and second embodiments illustrated in figures 4 and 5, this step 20 comprises a sub-step 21 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 21 comprises a phase 22 of pairing the first device 101 with the second device 102.

[0041] 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.

[0042] This sub-step 21 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 21, 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 22, the first device 101 or the second device 102, in particular 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.

[0043] In a first embodiment, the obtaining step 20 includes a sub-step 23 of exchanging the at least one security key between the first device 102 and the second device. This sub-step 23 includes: Phase 24, in which the first device 101 transmits the at least one security key to the second device 102; or Phase 25, in which the second device 102 sends the at least one security key to the first device 101.

[0044] 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 22, or a key derived from a key generated.

[0045] In a second embodiment, the obtaining step 20 includes 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, which may be based on a cryptographic algorithm such as, for example, the Diffie-Hellman algorithm.

[0046] With reference to figure 6, for a third embodiment of this obtaining step 20 similar to the second embodiment, it is foreseen that the sub-step 21 of establishing communication is replaced by 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. After this sub-step 27, this third embodiment includes, as in this second embodiment, a sub-step 28 in which the first device 101 and the second device 102 generate said at least one security key by implementing a key agreement protocol.

[0047] In the fourth embodiment shown in Fig. 7, the obtaining step 20 also includes a sub-step 29 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 20 then includes a sub-step 30 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 20 comprises a previous pairing phase implemented between the first device 101 and the second device 102, the keys generated during that pairing phase, or Derived from the generated key.

[0048] In a fifth embodiment of the obtaining step 20 depicted in FIGS. 8 and 9, this step 20 comprises: a substep 31 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 31 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 32 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.

[0049] In this fifth embodiment, the obtaining step 20 then comprises: a substep 33 of exchanging said at least one security key over a communications 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.

[0050] Sub-step 33 to replace a phase 35 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 36 of transmitting the at least one security key from the second device 102 to the first device 101 via the third device 103.

[0051] 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.

[0052] The method then includes a step 37 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.

[0053] 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.

[0054] That is, once the at least one security key is valid, in the method, the sub-steps 21, 27, 29, 31, 32 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.

[0055] 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.

[0056] This step 38 then comprises a sub-step 40 of designing a secure message by using said at least one security key and a payload. To do so, this sub-step 40 comprises a phase 41 of calculating a secure tag by implementing a tag algorithm using said at least one security key and a payload. This secure tag is a short piece of information that contributes to guarantee the integrity and / or authenticity protection of the message that contains the payload. This secure tag comprises 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 said at least one security key and a payload to calculate this secure tag.

[0057] This sub-step 40 then converts the calculated tag into Payload, or A phase 42 of generating a secure message by appending to the encrypted payload (if this designing sub-step 40 includes a phase 43 of encrypting the payload and / or a tag from an encryption algorithm using said at least one security key).

[0058] It should be noted that the payload and the tag may be encrypted during this encrypting phase 43. In this case, the sub-step referenced 40 includes a phase 42 of generating a secure message by encrypting a calculated tag that is appended to the payload. 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 and the tag.

[0059] 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.

[0060] 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.

[0061] The method then comprises a step 46 of processing data contained in a secure message received by the first device 101 from the second device 102. This step 46 comprises a sub-step 47 of extracting the payload contained in the received secure message.

[0062] This sub-step 47 includes a phase 48 of processing the secure tag by implementing a tag algorithm using the at least one security key and the payload contained in the secure message. During this phase 48, the processing unit 104 of the first device 101 may implement the tag algorithm (e.g. a MAC algorithm or a signature) using the at least one security key and the payload of the secure message to compute the tag.

[0063] The sub-step then comprises a phase 49 of verifying the consistency of the tag included in the secure message. The 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 tag included in the secure message is valid, 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, in particular of the payload, can be considered as unmodified.

[0064] If the designing sub-step 40 includes a phase of encrypting a payload, sub-step 47 may include a phase 50 of decrypting the encrypted payload contained in the received secure message.

[0065] During this decryption phase 50, 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 47, this phase 50 is performed before a phase 48 of processing a secure tag that requires the decrypted payload to be implemented.

[0066] It should be noted that if the tag and payload contained in the received secure message have been encrypted during the designing sub-step 40, the decrypting phase 50 may be performed before the processing of the secure tag phase 48.

[0067] The processing step 46 then includes a sub-step 51 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.

[0068] As will be apparent to those skilled in the art, various modifications may be made in the present disclosure without departing from the spirit or scope of the present disclosure. Accordingly, the present disclosure is intended to include modifications and variations of the embodiments of the present disclosure. For example, the method may be such that the advertised secure message includes only an encrypted payload without a secure tag.

Claims

1. A method of Bluetooth communication implemented between a first electronic device (101) and a second electronic device (102), comprising: This second electronic device (102) is capable of sending a secure message containing data to be processed by said first electronic device (101), The method comprises: - including a step (20) of each of the first and second electronic devices (101, 102) obtaining at least one security key, - The method, wherein the step (38) of the second electronic device (102) sending the secure message to the first electronic device (101) comprises a step (44) of establishing a communication link in Bluetooth advertising mode between the first and second devices (101, 102).

2. The obtaining step (20) a substep (21) of establishing a communication link between said first and second devices (101, 102) in Bluetooth connection mode, said substep (21) 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 The method of claim 1, wherein the key is derived from the generated key.

3. The obtaining step (20) - a substep (21) 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; The method of claim 1 , comprising:

4. 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) implementing a key agreement protocol; The method of claim 1 , comprising:

5. 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 the pairing phase, or The method of claim 1, wherein the key is derived from the generated key.

6. 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); The method of claim 1 , comprising:

7. The step of obtaining includes: - a substep (32) of establishing a communication link between said first device, second device and 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 said Bluetooth technology, or in a 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); The method of claim 1 , comprising:

8. The method according to claims 6 and 7, 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.

9. 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; 9. The method according to claim 1 , comprising:

10. The designing 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 (42) of generating the secure message by appending the calculated tag to the payload, or - a phase (42) of generating the secure message by appending the calculated tag to the payload, or The method according to any one of claims 1 to 9, characterized in that it comprises a phase (42) of generating the secure message by encrypting the calculated tag appended to the payload.

11. The method according to any one of claims 1 to 10, characterized in that it comprises a step (46) of processing data contained in the secure message received by the first device (101) from the second device (102).

12. The processing step (46) comprises: - extracting (47) the payload from the received secure message; - generating useful information based on the data contained in the payload of this secure message (51); The method according to any one of claims 1 to 11, characterized in that it comprises:

13. A system (100) for Bluetooth communication implemented between a first electronic device (101) and a second electronic device (102), comprising: 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), each of the first and second electronic devices (101, 102) is configured to obtain at least one security key; A system (100), wherein the step (38) of the second electronic device (102) sending the secure message to the first electronic device (101) includes a step (44) of establishing a communication link in Bluetooth advertising mode between the first and second devices (101, 102).

14. The system (100) includes the first and second devices (101, 102) and also a third electronic device (103), - exchanging said at least one security key over a communications link between the first and second devices (101, 102) via a third electronic device (103); or The system (100) according to any one of claims 1 to 13, further comprising a step in which the third electronic device (103) distributes the at least one security key to the first device and the second device (101, 102) via the communication link.

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