FR2987198A1 - METHOD FOR TRANSMITTING A MESSAGE INTO A DIGITAL INFORMATION STREAM - Google Patents

Abstract

The present invention relates to a method of transmitting a message M within an information stream, this stream comprising a broadcast signal D. In addition, this stream comprises successively a synchronization signal S and this message M. The present invention also relates to a method of receiving a message M in an information flow. In addition, this information flow comprising a diffusion signal D and a synchronization signal S followed by this message M, this method comprises the following steps: - acquisition of the synchronization signal S, - acquisition of the message M if and only if an activation signal appears during the synchronization signal S. The invention also relates to a transmission device and a reception device for carrying out the methods referred to above.

Description

METHOD FOR TRANSMITTING A MESSAGE INTO A DIGITAL INFORMATION STREAM

Description Technical Field of the Invention

The present invention relates to a method of transmitting a message within a digital information stream. The field of the invention is that of commercial promotion, essentially that of the distribution of coupons on identified products. State of the art

It is common that when you buy a magazine or any article, you get a coupon on another item. The distribution of these vouchers is done by means of a material support. Whether it is a coupon or any message of the same nature, it seems desirable to remove this material support for reasons well known to everyone. The present invention thus proposes to transmit a message without resorting to a hardware support. The invention also aims to provide a method of simple design, easy to use and inexpensive.

Disclosure of the invention. The invention firstly relates to a method of transmitting a message in a digital information stream, the latter comprising a broadcast signal; in addition, this digital information stream also comprises successively a synchronization signal and this message. The broadcast signal includes, for example, a television program broadcast over a wireless network or over a cable network. During this television broadcast, a flash such as an advertisement flash is emitted during the presence of the synchronization signal. Following this flash, a message such as a coupon is also transmitted over the network. Preferably, the transmission of the synchronization signal is preceded by the transmission of a validation signal.

The validation signal, as explained below, validates the message transmitted over the network. The second aim of the invention is a method of receiving a message in a digital information stream, the latter comprising a broadcast signal and a synchronization signal followed by this message, this method comprising the following steps: synchronization signal, - acquisition of the message if and only if an activation signal appears during the synchronization signal.

The activation signal materializes an action on the part of a person watching the television program, a necessary action during the synchronization signal to obtain the message.

Advantageously, the digital information flow further comprising a validation signal which precedes the synchronization signal, the activation signal is identical to the validation signal. In this case, this person must initiate by means of the activation signal an action which is determined by the validation signal. To facilitate this operation, the reception method comprises a step of displaying the validation signal.

Thirdly, the invention relates to a device for transmitting a message within a digital information stream, the device comprising a broadcasting means for transmitting a broadcast signal, further comprising transmission means for transmitting successively a synchronization signal and the message.

In addition, the transmitting means is further provided for transmitting a validation signal before the synchronization signal. Finally, the invention relates to a device for receiving a message in a digital information stream, the device comprising a reception means for receiving a broadcast signal, the information stream further comprising a synchronization signal. it comprises means for receiving the synchronization signal and acquisition means for acquiring the message if and only if an activation signal is present during the synchronization signal.

Preferably, the information flow comprising a validation signal which precedes the synchronization signal comprises means for receiving this validation signal, the activation signal having to be identical to the validation signal.

Advantageously, the reception device comprises a return means configured to restore the validation signal. According to a first additional feature of the invention, the receiving device comprises means for time stamping the message. According to a second additional feature of the invention, the receiving device comprises means for authenticating the message. According to a preferred embodiment, the receiving device comprises means for transmitting the message to a relay terminal. This relay terminal, preferably a portable terminal, makes it possible to transfer the message (the coupon) to another equipment (at a merchant). Description of the figures. Other advantages and characteristics of the invention will appear better on reading the description of a preferred embodiment which will follow, with reference to the appended drawings, carried out as indicative and non-limiting examples and in which: FIG. 1 schematically represents a broadcasting system for the implementation of the invention; FIG. 2 represents a time diagram of the digital information flow; FIG. 3 represents a first embodiment of a acquisition circuit for implementing the invention, and - Figure 4 shows a second embodiment of an acquisition circuit for carrying out the invention. The identical elements present in several figures are assigned a single reference.

Embodiments of the invention The method which is the subject of the invention makes it possible to generate an electronic coupon (C). Electronic coupon (C) means any electronic file evidencing a right to the user who holds it such as a discount on a particular purchase, or a gift offered for a particular purchase, etc. With reference to FIG. 1, the system for generating an electronic coupon, making it possible to implement the method that is the subject of the invention, comprises on the one hand a broadcasting equipment (11). The latter is configured to broadcast, through a broadcast network, a digital information stream (I) containing television programs. The term "broadcast network" means a network on which audiovisual content is broadcast by television channels and of the digital radio network, satellite network, cable network or other type. "Television program" means all or part of audiovisual content broadcast on a television channel, for example a film, television news, weather reports, game shows, etc. In practice, the broadcast equipment (11) comprises an electronic circuit which may comprise a microprocessor (13), one or more flash-type memories (14) of the flash, magnetic, optical or other type, and any other electronic component suitable for the skilled person. This broadcasting equipment (11) comprises, in particular, a transmission means (12) configured to broadcast these television programs over the air, satellite, internet, cable or other. This transmission means (12) can be in the form of an antenna, a dish, a telephone line, a cable line, etc. Referring to Figure 2, the digital information stream (I) transmitted by the broadcast equipment comprises a broadcast signal (D) containing a television program (E). During a television program (E), one or more commercials (P) may pause said television program or appear superimposed on said television program. The broadcast signal (D) therefore also contains the advertising flash (s) (P). Thus, the broadcast equipment comprises a broadcasting means for transmitting the diffusion signal (D) of known type.

For each advertisement flash (P), the digital information stream (I) transmitted by the broadcast equipment also comprises a synchronization signal (S). The latter is generated simultaneously with the advertising flash (P). This synchronization signal (S) comprises one or more time information in the form of digital data. For example, a data "start time" and data "end time", or data "start time" and data "duration", or several data pairs "start time" and "end time" or "start time" and "duration", or any other data or group of data suitable to those skilled in the art. The broadcast equipment (11) then comprises a transmission means. In practice, this transmission means comprises a microprocessor which, when executing the steps of a computer program stored in the memory integrated in the broadcast equipment (11), is configured to: - generate a synchronization signal ( S) from one or more predetermined time information, - transmitting the synchronization signal (S) within the digital information stream (I), via the transmission means (12). For each advertisement flash (P), the digital information stream (I) transmitted by the broadcast equipment (11) further comprises a message (M). The latter comprises one or more information relating to a right conferred on the user and being in the form of digital data. For example, a data "reduction" corresponding to a reduction on a purchase, or a data "offered" corresponding to a gift offered for a purchase, or any other data or group of data suitable for the skilled person. In practice, the transmission means of the broadcast equipment (11) comprises a microprocessor which, when it executes the steps of a computer program stored in the memory integrated in said broadcast equipment, is configured to: generate a message (M) from one or more information relating to a right conferred on the user, - sending the message (M) within the digital information stream (I), via the transmission means (12) . The message (M) is transmitted beforehand simultaneously or as a result of the synchronization signal (S). For each advertisement flash (P), the digital information stream (I) may optionally comprise, in addition to the signals previously described, a validation signal (V). The latter, if any, is preferably produced before or at the beginning of the advertising flash (P), but may also be produced at different or several times of said advertising flash (P). The validation signal (V) comprises one or more information relating to a procedure to be followed by the user to generate an electronic coupon (C), and which is in the form of digital data. For example, a data item "instruction" corresponding to the procedure to be followed by the user to generate an electronic coupon (C). In practice, the transmission means of the broadcast equipment (11) comprises a microprocessor which, when it executes the steps of a computer program stored in the memory integrated in said broadcast equipment, is configured to: - generating a validation signal (V) from one or more information relating to a procedure to be followed by the user to generate an electronic coupon (C), - transmitting the validation signal (V) within the flow of digital information (I), via the transmission means (12). The transmission means optionally transmits the enable signal (V) before the synchronization signal (S). With reference to FIG. 1, the system for generating an electronic coupon comprises, on the other hand, a digital receiver (13) generally connected to a means (14) for receiving the digital information stream (I) broadcast from the type antenna, dish, telephone line, cable line, or others. The digital information flow (I) is therefore transmitted by the broadcast equipment (11) to a digital receiver (13). The digital receiver (13), which can be integrated with the digital television, is configured to process the broadcast digital information stream (I). This processing is generally of the demodulation, decoding, decryption or other type. Once the digital information stream (I) has been processed, it is sent to a means for rendering said digital information stream generally integrated with the television. This means of reproduction is of the LCD screen, plasma, OLED, SED, or other type, for the video components, and the type of amplifier and speakers for the audio components. In practice, the digital receiver (13) comprises an electronic circuit that may include a tuner, a demodulator, a decoder, a microprocessor, one or more memories of the flash, magnetic, optical or other type, etc.

This digital receiver (13) is generally provided with a control member (15), such as an infrared or wifi remote control, a mobile phone communicating via wifi and equipped with software for controlling said digital receiver, a means of voice control, gesture control means, or any other control device suitable for those skilled in the art.

According to a first option, this digital information stream (I) does not include a validation signal (V). Receiving a digital information stream (I), the digital receiver (13) receives the broadcast signal (D) containing a television program (E) and one or more commercials (P). For the sake of simplicity, we will speak only of an advertising flash (P) in the following description, but the process can be applied independently for each of the advertising flashes. To do this, the digital receiver (13) comprises a reception means configured to receive the broadcast signal (D). This receiving means is generally in the form of a tuner connected to the broadcast network via the receiving means (14). The digital receiver (13) also receives the synchronization signal (S). To do this, the digital receiver (13) comprises receiving means configured to receive the synchronization signal (S). This receiving means is generally in the form of a tuner connected to the broadcast network via the receiving means (14). The digital receiver (13) then detects the synchronization signal (S) via a detection means. In practice, the digital receiver detection means (13) comprises a microprocessor which, when executing the steps of a computer program stored in a mass memory, is configured to: - find in the digital information stream ( I), a possible synchronization signal (S), - if necessary, extract the data contained in the synchronization signal (S). Upon receiving the digital information stream (I), the digital receiver (13) also receives the message (M). To do this, the digital receiver comprises a reception means configured to receive the message (M). This receiving means is generally in the form of a tuner connected to the broadcast network via the receiving means (14). However, the acquisition of the message (M) is conditioned by the reception of an activation signal (A). The user must then trigger the activation signal (A) during the occurrence of the synchronization signal (S) to authorize the acquisition of the message (M). The activation signal (A) is initiated by an activation means. In particular, the activation signal (A) can be initiated by pressing an identified key or any key on the remote control, the digital receiver (13), a mobile phone, or any other electronic equipment. suitable for those skilled in the art. The activation signal (A) may also be initiated orally by pronouncing key words recognized as an activation signal by a voice recognition means integrated in the digital receiver (13), an expansion card, a a remote box, etc. The activation signal (A) can still be initiated by gestures, by performing gestures recognized as an order by a gesture recognition means integrated into the digital receiver (13), an expansion card, a box deported, on the remote control, to a telephone, etc.

Upon receiving the activation signal, the digital receiver (13) acquires the message (M). To do this, the digital receiver comprises an acquisition means configured to extract the message (M) from the digital information stream (I). In practice, the acquisition means of the digital receiver (13) comprises a microprocessor which, when it performs the steps of a computer program stored in a memory, is configured to: - find in the digital information stream (I ), the message (M), - extract the data contained in the message (M). By way of example, with reference to FIG. 3, this message acquisition function (M) can be realized simply by means of an acquisition logic circuit. The synchronization signal (S) and the activation signal (A) are applied as inputs to an AND gate (21). A switch (22) receives as input the message (M), has its output connected to a memory (23) and is controlled by the output of the AND gate (21).

The acquisition of the message (M) can thus be done in a memory (23). The memory (23) in which the data of the message (M) is stored can be of the flash, magnetic, optical or other type and for example be in the form of a hard disk, a USB key, a memory card, etc. The memory can be integrated in the digital receiver, the television, an expansion card, or be transferred to equipment available on a telecommunication network (18), etc. The term telecommunications network (18) is understood to mean a network of the intranet network, Internet network, telephone network or other type.

According to a second option, the digital information flow (I) comprises a validation signal (V). The digital receiver receives the broadcast signal (D), the synchronization signal (S), and the message (M) in the same manner as previously described for the first option. The digital receiver (13) then detects the synchronization signal (S) as previously described for the first option. Again, the acquisition of the message (M) is conditioned by the receipt of an activation signal (A) triggered by the user as described above. However, unlike the first option, the activation signal must conform to the enable signal (V). Thus, by receiving the digital information stream (I), the digital receiver (13) also receives the validation signal (V). To do this, the digital receiver comprises a reception means configured to receive the validation signal (V). This receiving means is generally in the form of a tuner connected to the broadcast network via the receiving means (14). Then, the digital receiver (13) acquires the validation signal (V). To do this, the digital receiver comprises an acquisition means configured to extract the validation signal (V) from the digital information stream (I). It goes without saying that the digital receiver renders either directly the validation signal, a number or a symbol for example, or indirectly by means of an announcement that identifies this validation signal, a sentence containing this figure or symbol for example. In practice, the acquisition means of the digital receiver (13) comprises a microprocessor which, when it performs the steps of a computer program stored in a memory, is configured to: - find in the digital information stream (I ), the validation signal (V), - extracting the data contained in the validation signal (V), typically the "instruction" data item, - sends the data contained in the validation signal (V) to the restitution means to generate an announcement on how to generate an electronic coupon (C). This announcement may be audible or readable and indicate to the user the key on which to press, the gesture to be performed, the voice command to be spoken, or other, so as to generate the electronic coupon (C). When this message is readable, it can obscure all or part of the screen, be generated superimposed or be directly integrated with the advertising flash. The announcement is made in a manner at the beginning or during the occurrence of the synchronization signal (S) so that the user can trigger the activation signal (A) pending said occurrence of the synchronization signal. As an example, it may be, to trigger the activation signal (A), to press the key of the remote control on which is written the symbol "*", the announcement generated by the means of reproduction being in the form of an inscription overprinting the advertising flash (P) on which is shown: "if you wish to benefit from this coupon, press the * key on your remote control". In this case, the activation signal and the validation signal correspond to an identified key of the remote control.

Therefore, to authorize the acquisition of the message (M), the user must trigger an activation signal (A) which is identical to the validation signal (V) during the occurrence of the synchronization signal (S). Upon receipt of the activation signal, the digital receiver (13) therefore compares the activation signal (A) with the enable signal (V). If these correspond, the digital receiver (13) acquires the message (M). To do this, the digital receiver comprises an acquisition means configured to compare the activation signal (A) and the validation signal (V), and extract the message (M) from the digital information stream (I). In practice, the acquisition means of the digital receiver (13) comprises a microprocessor which, when executing the steps of a computer program stored in a memory, is configured to: - compare the activation signal (A) with the validation signal (V), and if the activation signal (A) with the validation signal (V): o find in the digital information stream (I), the message (M), o extract the message (M) of the digital information stream (I). By way of example, with reference to FIG. 4, this message acquisition function (M) can be realized simply by means of another acquisition logic circuit. The enable signal (V) and the acquisition signal (A) are applied as inputs to a comparator (31). An AND gate (32) receives as inputs the output signal of the comparator (31) and the synchronization signal -14- (S). A switch (33) receives at the input the message (M), at its output connected to a memory (34) and is controlled by the output of the AND gate (32). The acquisition of message M can thus be done in a memory (34) of the type of that previously described. In alternative embodiments, the activation signal (A) can comprise several actions in response to several announcements contained in the validation signal (V) during the occurrence of the synchronization signal (S). For example, to trigger the activation signal (A), may have to press: - at the beginning of the advertising flash (P), on the key of the remote control on which is written the character "a", - at the end of the flash (P), the button on the remote control on which is written the character "b". The procedure to be followed by the user contained in the validation signal (V) can then contain two announcements. A first announcement, generated by the means of reproduction, is in the form of an inscription, superimposed, at the beginning of the advertising flash (P), on which appears: "if you wish to profit from this coupon, press the key a of your remote control. A second announcement, generated by the means of reproduction, is in the form of an inscription, superimposed, at the beginning of the advertising flash (P), on which appears: "if you wish to profit from this coupon, press the a key on your remote. In order to avoid duplication of the message and thus the rights associated with it, it may be advantageous to secure the message (M). Thus, once the message (M) acquired, the digital receiver (13) can generate an electronic coupon (C) containing said message and a digital signature for authenticating said message (M). The digitally signed electronic coupon (C) 30 then becomes unique and tamper-proof. The digital signature is generated by an encryption function based on a digital encryption algorithm using a private encryption key and may include hashing steps using MD5 or SHA type hash functions. In order to increase the security of the message (M), the file can also be encrypted. In practice, a generation means equipping the digital receiver (13) comprises a microprocessor which, when executing the steps of a computer program stored in a memory, is configured to: generate a digital signature associated with the message (M) , - generate a file containing the message (M) and the digital signature, - optionally, encrypt the file. Still with the aim of increasing the security of the message (M), the digital receiver (13) may also include means for time stamping said acquired message (M). This time stamp later makes it possible to verify that the message has been acquired when it was to be, that is to say during the advertising flash (P). The time stamp comprises information relating to the moment of acquisition of the message (M), said information being in the form of digital data. The latter can, for example, be a datum "date" and a datum "hour". In practice, a time stamping means equipping the digital receiver (13) comprises a microprocessor which, when it performs the steps of a computer program stored in a memory, is configured to retrieve the data "date" and "time" relating to the moment of acquisition of the message (M). The generation means equipping the digital receiver (13), will then generate a file containing the message (M), the digital signature and the time stamp, that is to say the data "date" and "hour". The electronic coupon (C) is then stored in a memory of the type previously described. The electronic coupon (C) is then in the form of a file, encrypted or not, and containing: - the message (M), -16- - the digital signature, possibly the timestamp. Returning to Figure 1, the digital receiver (13) is also adapted to communicate with a portable terminal (16), a smartphone ("Smartphone" in English) for example. This digital receiver (13) is therefore provided with a wired transfer means (network card, USB card, HDMI card, or other) or wireless (Wifi chip, Bluetooth chip, NFC chip, infrared transmitter, or others. It should be noted that all or only some of the means mentioned previously and equipping the digital receiver (13) can be integrated into a PCMCIA type expansion card intended to be inserted in a common interface port present on said digital receiver, or be integrated into a remote electronic box and be connected to said digital receiver by a wireless connection (Wifi, Bluetooth, infrared, NFC, or other) or by a wired connection (USB, Ethernet, or other). Similarly, the microprocessors of the various means equipping the digital receiver (13) can be in the form of a single microprocessor that can fulfill all the functions associated with all the means, or several microprocessors can each perform several functions different ways. The portable terminal (16) then comprises a communication means 25 adapted to cooperate with the transfer means, and of the same type as the transfer means described above. Thus, the link between the transfer means and the communication means can be of any type: - wired link such as USB, Ethernet cable, etc ... - wireless link such as radio, infrared or generally any link electromagnetic as the so-called "NFC" for "Near Field Communication" in English. The transfer of the message from the digital receiver (13) to the portable terminal (16) can be initiated by one or other of these devices. Optionally, when the connection is established, the digital receiver (13) can perform authentication of the portable terminal (16), said portable terminal having been previously registered with said digital receiver. From now on, the portable terminal (16) is in possession of the message (M).

The latter is generally contained in the electronic coupon (C). The portable terminal (16) can in turn transfer the message (M) to a payment terminal (17). To do this, the payment terminal (17) comprises a transfer means of the same type as that described above.

Remember that the message in question is a coupon, a promotional offer, or other. Thus, the payment terminal (17) analyzes the information recorded in the message and calculates the amount of what remains to be paid given the specified reduction. In practice, a means of analysis equipping the payment terminal (17) comprises a microprocessor which, when executing the steps of a computer program stored in a memory, is configured to: - optionally, decrypt the electronic coupon ( C), - extract the data contained in the message (M) relating to the right conferred on the user, - calculate the amount that the user must pay according to his purchases and the right conferred on the user. For example, if the message contains a "Z% voucher on product X". If the user buys the product X having an advertised price Y, and said user transfers the electronic coupon (C) of his mobile terminal to the payment terminal (17), the latter calculates the amount that the user must pay in deducting Z% of the advertised price Y of the product X. -18- Optionally, before proceeding to the collection, the payment terminal (17) can carry out certain verifications. These verifications can be carried out locally by the payment terminal (17), or from a remote server (19) connected to said payment terminal via a telecommunications network (18). These verifications concern one or more of the following operations: - verification of the authenticity of the electronic coupon (C), - verification of the timestamp of the electronic coupon (C), - verification of the uniqueness of the electronic coupon (C), - registration of the use of the electronic coupon (C), - confirmation of the validity of the electronic coupon (C). The verification of the authenticity of the electronic coupon (C) consists in checking the validity of the digital signature. In practice, a verification means equipping the payment terminal (17) or the remote server (19) comprises a microprocessor which, when it executes the steps of a computer program stored in a memory, is configured to: - extract the digital signature of the electronic coupon (C), - verify the authenticity of the digital signature, in practice by means of a decryption function and the private encryption key. The verification of the timestamp of the electronic coupon (C) consists in verifying that the message (M) has been acquired during the broadcasting of the advertising flash. In practice, a means of verification equipping the payment terminal (17) or the remote server (19), comprises a microprocessor which, when executing the steps of a computer program stored in a memory, is configured to: - extract the timestamp of the electronic coupon (C), -19- - compare the timestamp with the time period or slots during which the advertising flash P associated with the message has been broadcast, the time period or times being previously recorded in a database.

The verification of the uniqueness of the electronic coupon (C) consists in checking that the electronic coupon (C) has not already been used. In practice, a verification means equipping the payment terminal (17) or the remote server (19) comprises a microprocessor which, when it performs the steps of a computer program stored in a memory, is configured to check that the electronic coupon (C) is not listed in a database listing electronic coupons already in use. The registration of the use of the electronic coupon (C) consists in recording the electronic coupon in a database so that it can no longer be used later. In practice, a means of registration equipping the payment terminal (17) or the remote server (19) comprises a microprocessor which, when executing the steps of a computer program stored in a memory, is configured to record the memory. use of the electronic coupon (C) in the database listing the electronic coupons already used. The confirmation of the validity of the electronic coupon (C) consists in authorizing the payment terminal (17) to use the message (M) to generate the invoice when said electronic coupon is authentic, that it has never been used, and that its timestamp coincides with the time slots during which the advertising flash P has been broadcast. Ultimately, the payment terminal (17) can calculate the amount according to the right conferred to the user only if the electronic coupon (C) is valid, otherwise, the price to be paid by the user being the price advertised Y of the product X. In practice, a validation means equipping the payment terminal (17) or the remote server (19) comprises a microprocessor which, when it executes the steps of a stored computer program in a memory, is configured to give the order to calculate the amount according to the right conferred to the user when the electronic coupon (C) is authentic, that it has never been used, and that its timestamp coincides with the time slots during which the advertising flash P has been broadcast. The embodiments of the invention presented above have been chosen in view of their concrete nature. It would not be possible, however, to exhaustively list all the embodiments covered by this invention. In particular, any step or any means described may be replaced by a step or equivalent means without departing from the scope of the present invention.

Claims (14)

REVENDICATIONS1. A method of transmitting a message (M) within a digital information stream (I), said stream comprising a broadcast signal (D), characterized in that the digital information stream (I) also comprises successively: - a synchronization signal (S), - said message (M). 10 2. Transmission method according to claim 1, characterized in that the transmission of said synchronization signal (S) is preceded by the transmission of a validation signal (V). 15 Method for receiving a message (M) in a digital information stream (I), characterized in that, the digital information stream (I) comprising a broadcast signal (D) and a synchronization signal ( S) followed by this message (M), this method comprises the following steps: 20 - acquisition of the synchronization signal (S), - acquisition of said message (M) if and only if an activation signal (A) appears during said synchronization signal (S). 4. The reception method as claimed in claim 3, characterized in that the digital information stream (I) additionally comprises a validation signal (V) which precedes said synchronization signal (S), said activation signal ( A) is identical to said validation signal (V). 5. Reception method according to claim 4, characterized in that it comprises a step of displaying said validation signal (V). 6. Device for transmitting (11, 12) a message (M) within a digital information stream (I), device comprising a broadcasting means for transmitting a broadcast signal (D), characterized in that it further comprises a transmission means for successively transmitting a synchronization signal (S) and said message (M). 7. Transmission device (11, 12) according to claim 6, characterized in that said transmitting means is further provided for transmitting a validation signal (V) before said synchronization signal (S). 8. Device for receiving (13, 14) a message (M) within a digital information stream (I), device comprising receiving means for receiving a broadcast signal (D), characterized in that that, the digital information stream (I) furthermore comprising a synchronization signal (S), it comprises means for receiving said synchronization signal (S) and acquisition means for acquiring said message (M) if and only if an activation signal (A) is present during said synchronization signal (S). 9. receiving device (13, 14) according to claim 8 characterized in that, the digital information stream (I) comprising a validation signal (V) which precedes said synchronization signal (S), it comprises a means to receive this enable signal (V), said activation signal (A) to be identical to said enable signal (V). 10. receiving device (13, 14) according to claim 9, characterized in that it comprises a restitution means configured to restore said validation signal (V) .- 23- 11.Dispositif reception (13, 14) according to any one of claims 8 to 10, characterized in that it comprises means for time stamp said message (M). 12.Dispositif reception (13, 14) according to any one of claims 8 to 11, characterized in that it comprises means for authenticating said message (M). 13.Acceptance device (13, 14) according to any one of claims 8 to 12, characterized in that it comprises means for transmitting said message (M) to a relay terminal (16).