HK1029689B

HK1029689B - Method and system for ensuring the security of service supplies broadcast on a computer network of the internet type

Info

Publication number: HK1029689B
Application number: HK00107943.3A
Authority: HK
Inventors: Rosset Franck; Gayet Alain; Moulin Jean
Original assignee: Audiosmartcard International S.A.
Priority date: 1996-09-25
Filing date: 1997-09-25
Publication date: 2004-10-15

Description

The field of the invention is that of data transmission over a computer network such as the Internet.

More specifically, the invention relates to a process and system which enables users of an Internet-type computer network with multimedia terminals with a microphone and connected to an Internet-type computer network, located at a distance from a service provider, to access in a secure and rapid manner the services that that service provider provides to its subscribers by means of an Internet-type computer network.

The problem is to prevent a malicious user from accessing services offered by service providers without authorization, without paying the corresponding fees or by claiming that he has not requested the services charged to him.

The problem of the 'closed' access key is a problem which is not only a problem of the user's own choice but also a problem of the user's choice of the user's choice of access key.

It has been proposed (document WO 96 04741 in the name of Andrew MARK) that a card emitting an acoustic, encrypted DTMF-type signal be used to dial telephone numbers, so that the holder of such a card, by coupling it to the microphone of the telephone handset, automatically transfers his identification.

Since these identifiers are encrypted, it is likely that no one else will be able to understand their contents.

The A. MARK solution therefore concerns a completely different technical area than that of the security of data transmitted over a computer network such as the Internet. Furthermore, the recording of the signals emitted by the A. MARK card is still possible and a fraudster with such a recording can substitute himself for the cardholder. The A. MARK card would therefore not prevent a malicious user from accessing, without authorisation, the services offered on computer networks such as the Internet.

The patent application: DE,A,43 25 459 filed in the name of Raymund H. EISELE describes a calculator which emits acoustic identification signals, varying with each operation. A recording of such acoustic signals would therefore be of no interest to a fraudster. However, its large size, low maneuverability, difficulty in use and high cost do not allow the objectives of the present invention to be achieved. Namely: to design a process and system which is convenient to use, fast to implement and economical.

The objectives of the present invention are achieved and the problems arising from the techniques of the present invention are solved, according to the invention, by the following process: the service provider makes available to each user of an Internet-type computer network who has subscribed to its services a credit card format, which is personalised by means of specific identifiers for each subscriber and for each card; the credit card format shall emit short DTMF-type acoustic identification signals, at least partially encrypted, which vary with each operation when activated by the Internet-type computer network user,the said acoustic identification signals are received by the microphone of the multimedia terminal and transmitted via the Internet-type computer network to the IT department of the service provider, in particular after the multimedia terminal has received a transmission order from the IT department,the transmitted signals and the customer and card identification data held by the IT department are processed and compared electronically by the IT department of the service provider, so that in the event of a coincidence, the subscriber is immediately put in touch with the service provider's computer server.

The service provider is thus assured that the caller has a genuine card and not a computer decoy. It has also been able to identify the cardholder as a person authorised to use the services it offers. Furthermore, fraudsters do not have the possibility to steal the identification data as these are transmitted automatically in encrypted form. Furthermore, the recording, in any form, of acoustic signals will be of no use to a fraudster in being identified by the service provider's computer services. Indeed, the acoustic identification signals vary with each operation. That is, each time the card is activated.

Preferably the card: further calculates the number of times C ((p,n) it is actuated,emits acoustic signals representative of the number of times C ((p,n) it has been actuated,encrypts the acoustic signals according to the number of times C ((p,n) it has been actuated.

Preferably also, the said IT means for processing and comparing electronically the transmitted signals and the customer and card identification data held by the IT department of the service provider: remember the number of times C(p,m) the card was activated during the last validated operation,compare the number of times C(p,n) the card was activated during the current operation with the number of times C(p,m) the card was activated during the current operation,reject the current operation if C(p,n) is less than or equal to C(p,m) and continue the verification of the current operation if C(p,n) is greater than C(p,m),recalculate the electronic signals S'(p,n) in identification data and the number of times C(p,n) the card was activated during the current operation,compare the signals to the electronic signals S,n. In case of coincidence, the subscriber can be immediately put into communication with the service provider.

It should be noted that the use of a microcircuit to encrypt, by means of a meter, identification codes exchanged between a transmitter and a receiver was described in patent application: EP 0 459 781 A1 filed on behalf of NANOTEK LIMITED.

In order to increase the security of the process, in one embodiment the process also includes the following step: the subscriber issues, by means of a keyboard associated with the multimedia terminal and/or the card, a confidential code; after transmission to the IT department of the service provider, via the communication IT network, this confidential code is processed and compared with the subscriber's personal confidential code held by the IT department of the service provider.

The insurance provider you call is the person who is authorized to contact the insurance provider, and a stolen card cannot be used by a thief unless he knows the secret code.

In another embodiment, in order to also enhance the process's security and to avoid the possibility for the subscriber to challenge the request he has made to the service provider, the process also includes the following steps: the orders given by the subscriber to the service provider are validated by the subscriber by activating the card to emit an encrypted acoustic validation signal,the validation signal is recorded by the service provider's IT department, processed and decrypted, and preferably an acknowledgement of receipt is sent to the subscriber.

The subscriber has thus validated the order he has placed with the service provider by means of an electronic signature.

At least three embodiments allow the transmission of the identification acoustic signals to the service provider's IT department.

According to the first variant, the process of the invention also includes the following steps: the service provider's IT service downloads a conversion software into the multimedia terminal,the conversion software converts,in the form of a bit sequence,the acoustic identification signals received by the microphone of the multimedia terminal,the bit sequence is transmitted, via the Internet-type computer network,to the service provider's IT service,in particular after receipt of a transmission order from the IT service.

So the signals coming from the multimedia terminal are in the form of a sequence of bits.

In the second embodiment, the acoustic identification signals received by the microphone of the multimedia terminal are transmitted via the Internet-type computer network to the IT department of the service provider, in particular after the multimedia terminal receives a transmission order from the IT department. In this embodiment, the signals from the multimedia terminal are transmitted in the form of an audio file. The processing of the audio file and its transformation into a sequence of bits (binary elements) is carried out by the IT services of the service provider.

According to the third variant, the process also includes the following steps: the service provider makes available to each Internet-type computer network user who has subscribed to its services, a conversion software to be implemented in the multimedia terminal,the said acoustic identification signals received by the multimedia terminal microphone are converted into a sequence of bits, before being transmitted via the Internet-type computer network to the service provider's IT department.

The invention also concerns a system which enables users of the Internet-type computer network with multimedia terminals with a microphone and connected to an Internet-type computer network, located at a distance from a service provider, to access in a secure and rapid manner the services offered by the said service provider to users.

In particular: The system according to the invention consists of a card, in the format of a credit card, personalized with specific identifiers for each card and for each subscriber, made available to them. * means of emitting short identification signals, of the DTMF type, operated by the subscriber by means of an element accessible from outside the card*, means of encryption allowing at least partial encryption and variation of the acoustic signals each time the card is operated.The system of the invention includes means of transmitting acoustic signals, located in multimedia terminals, transmitting acoustic signals remotely in the form of electronic signals, via the so-called Internet-type computer network.The system of the invention includes computer means, dependent on the IT services of the service provider, connected to the Internet-type computer network and receiving electronic signals from multimedia terminals. * a database containing the references of cards and subscribers and their identification data*, the means of processing and comparing the electronic signals and identification data contained in the database.

This means that in the event of a coincidence, the services of the service provider are immediately accessible to subscribers.

The system ensures that the caller has a genuine card and not a computer fraud. It also allows the cardholder to be identified as a person authorised to use the services it offers. Furthermore, fraudsters cannot steal the identification data as they are transmitted automatically in encrypted form. Furthermore, the recording of acoustic signals in any form will not be of any use to a fraudster in identifying himself by the service provider's computer services.

The card shall preferably also contain: an incremental meter interconnected to the means of emission and encryption, incrementing by at least one unit each time the card is activated.

Thus the state of the incremental meter is transmitted to the computer and the acoustic signals are encrypted according to the state of the incremental meter.

Preferably also the said IT means shall also include: means of storing the state C ((p,m) of the incremental meter during the last validated operation,means of comparing the state C ((p,n) of the incremental meter issued during the current operation with the state C ((p,m) of the stored incremental meter.

So the verification of the current operation is rejected if C ((p,n) is less than or equal to C ((p,m) and is continued if C ((p,n) is strictly greater than C ((p,m).

Preferably, the means of processing and comparison of the electronic signals and identification data contained in the database should also include means for recalculating the electronic signals according to the state C ((p,n) of the incremental meter and the identification data and then comparing them with the transmitted electronic signals, so that in the event of a coincidence, the subscriber can be immediately put in contact with the services of the service provider.

In order to increase the security of the system, in one embodiment the system also includes secondary means of comparing a personal subscriber confidential code contained in the database with a confidential code issued by the subscriber.

The service provider is thus assured that the caller is the person authorized to contact the service provider.

In another embodiment, also to enhance the security of the system and to prevent the subscriber from being able to challenge the request he has made to the service provider, the system consists of: software means for validating orders given by the subscriber to the service provider, after detection of an encrypted acoustic signal issued by the card operated by the subscriber,software means for issuing an acknowledgement of receipt of orders given to be sent to the subscriber.

The subscriber has validated the order he has placed with the service provider by means of an electronic signature.

According to the first variant, the IT resources, which depend on the IT services of the service provider, include: * means of downloading a converter software into the multimedia terminal, the so-called converter software converts, in the form of a bit sequence, the acoustic identification signals received by the microphone of the multimedia terminal, * means of issuing an order for the transmission of the bit sequence, from the multimedia terminal to the IT services of the service provider, via the Internet-type computer network.

According to the second embodiment, the multimedia terminal comprises means of transmitting the acoustic identification signals received by the microphone of the multimedia terminal in the form of an audio file. This audio file is transmitted via the Internet-type computer network to the service provider's IT department, in particular after receipt of a signal from the service provider's IT services. In this variant, the processing of the audio file and its transformation into a sequence of bits is carried out by the service provider's IT services.

The third variant is that the system includes a conversion software to be implemented in the multimedia terminal, which converts the acoustic signals received and transmitted by the multimedia terminal microphone into bit sequences that can be transmitted remotely via the Internet-type computer network.

Other features and advantages of the invention will be apparent from the description of embodiments of the invention, given as an indicative and non-limiting example. 1 : a schematic view in perspective of the system and process according to the invention,Figure 2 : the card in the form of a block diagram,Figure 3 : the algorithm for verifying the authenticity of the transmitted signal.Figure 4 : in the form of a diagram, the first embodiment, characterized by the IT services of the service provider downloading a conversion software into the multimedia terminal,Figure 5 : in the form of a block diagram, the so-called second embodiment, characterized by the IT services of the service provider receiving a sound file transmitted by the multimedia terminal,Figure 6 presents, in the form of the so-called block diagram, the third embodiment, characterized by the IT services of the service provider receiving bits generated by means of a multimedia terminal software.

The system and process of the invention are now presented in relation to Figure 1.The system and process of the invention enable users 11 of the Internet-type computer network 15 with multimedia terminals 16 with a microphone 17 to access in a secure and rapid manner the services 30 that the service provider 12 provides to users 11.The multimedia terminal 16, located at a distance from the Internet-type computer services 18 of the service provider 12, is connected to the Internet-type computer network 15.

The system consists of a card 10, in the format of a credit card, personalized by specific identifiers for each card and for each subscriber 11. This card is made available to subscriber users 11 by the service provider 12 and its services 40. The card 10 has broadcast means, including a speaker 13 that emits short DTMF-type identification acoustic signals 20. These signals are emitted when the broadcast means 13 and the bodies that control them are actuated by the customer using a button 14 accessible from the outside of the card (not visible in Figure 1 because located on the other side of the card). These broadcast means 13 are comprised of a DTMF 99, 104 signal generator controlled by a microprocessor powered by a battery and controlled by a 108.101010 microprocessor for each subscriber. The card 1010 and 108.1010 are encrypted using at least one cryptographic algorithm, each of which contains at least 10 microprocessors and 10 microprocessors.

The system also includes transmission means 19 of the 20 acoustic signals, located in the multimedia terminal 16. These transmission means 19 transmit the acoustic signals remotely, after processing and conversion into electronic signals, via the Internet-type computer network 15.

The system also includes 21 IT means, which are dependent on the IT services 18 of the service provider, connected to the Internet-type computer network 15 and receive signals from the multimedia terminals 16.

The IT means 21 include: * means of operating 22 the means of transmission 19 of the multimedia terminals 16* a database 23 containing the references of cards and subscribers and their identification data* means of processing 24 and means of comparison 25 of the electronic signals and identification data contained in the database 23* identification data contained in the database 23 and characteristic data of subscribers and cards.

Thus, in the event of a coincidence, the services 30 of the service provider 12 are immediately accessible to subscribers.

The microprocessor 104 and the encryption means 103 are designed in such a way that the acoustic signal 20 varies with each operation. Indeed, to encrypt an identification code is to transform it into a series of information, incomprehensible to everyone, and that only the holder of the encryption key can decrypt. But this does not prevent the copy of the encrypted identification code, either during its acoustic transmission (magnetophone), or by hacking the telephone line. This copy, used improperly by a fraudster, will be treated by the receiver system having all the characteristics of the original, then interpreted as the identifiers in order to verify the card.

The problem thus arises: how to make any attempt at reproduction impossible? Various variants of the general method of distinguishing between the original and the copy, when analysing the encrypted signal received by the computer means 21, by inserting a distinctive element into the DTMF type signal 20 emitted by the card 10 will be described below.

Err1:Expecting ',' delimiter: line 1 column 238 (char 237)

Another variant is to use incremental lists (for example, as described in US Patent No. 4 928 098). The transmitting and receiving devices have the ordered list of the successive encryption of the identification code or have algorithms to establish them as they go. At a given moment the computer means 21 are waiting for the encrypted result Cn. If they actually receive the message Cn, it validates the operation.Err1:Expecting ',' delimiter: line 1 column 427 (char 426)in the state C(n+p+2), If the latter is different, the message is not validated and the analysis system remains waiting for the message C(n).

In a preferential embodiment, to distinguish the original signal from its copy, the microprocessor 104 embedded in card 10 has an incremental counter 105. With each use of the card, the incremental counter 105 increases by one or more units.

In the case of this embodiment, the state C(p,n) 242 of the meter 105 is included in the calculation of the encrypted message 244 issued by the means of transmission 13. The coded part S(p,n) 241 is calculated by algorithm 108 (whose equivalent algorithm 247 is stored in the computer means 21) by means of the secret key 250 specific to each card and the state C(p,n) 242 of the meter 105. The card 10 emits, in addition to the identification number I(p) 240 of the card and the encrypted identification code S (p,n) 241, the cryptographic state C (p,n) 242 of its meter 105 incrementally with each transmission.In the database 23, the state C ((p,n) 242 of the incremental counter 105 at the last validated operation. Thus, at each receipt of message 244, the comparison means 25 of the computer means 21 can compare 245 the information received relating to the state C ((p,n) 242 of the counter 105, with the previous information received C ((p,m) 246 and stored in memory 23. (a) - If the state C ((p,n) 242 of the meter 105 (fig. 2) expressed in message 244 is strictly higher (n > m) than the previously received C ((p,m) 246, then message 244 is accepted and the analysis continues.If n) 242 of the number 105 expressed in message 244 is less than or equal (n ≤ m) to the number C ((p,m) 246 previously received, the message is rejected.

If the conditions set out in point (a) above are met, the computing means 21 can read the fixed part I ((p) 240 and search in their own database 23, 230 for the corresponding secret key of the card. The computing means 24 can then, by means of algorithm 247, the meter state C ((p,n) 242 and the secret key C ((p,n) 250, calculate the encrypted code expected by the computing means 21. The encrypted code S' ((p,n) 248 thus calculated is compared 249 to the one actually received S ((p,n) 241, by means of the comparison of 25. This and these means therefore allow the validation or invalidation of the message 244 without the user having to perform the action of changing the card several times, as in the case of the variation described above.

The existence of an incremental counter 105 within card 10 allows the maximum number of times the card can be used to be set at the time of individual programming of the card at no additional cost.

The 244 frame issued shall contain, for a given card (p), a fixed part I(p) 240 (the card identification number),an incremental variable part C(p,n) 242 (the meter state),an apparently random variable part S(p,n) 241 (the result of an encryption algorithm 108 on the secret key 250 specific to that card (p))

The frame emitted is always different from one card to another, is, for a given card, always different at each show.

Err1:Expecting ',' delimiter: line 1 column 639 (char 638)

Thus, by means of this combination of means, it is possible to emit, by means of a card having the format of a credit card, identification DTMF-type acoustic frequencies, receivable by the microphone of a telephone network connected equipment, and to be certain of the authenticity of the calling card and thus to exclude all fraudsters using any sound recording or computer or any computer deception.

In order to increase the security of the system, in the embodiment shown in Figure 1, the system also includes second comparison means 26. These means of comparison allow a personal confidential code to the subscriber contained in the database to be compared with the confidential code issued by the subscriber.

The service provider is thus assured that the caller 11 is the person authorized to contact the service provider.

In order to enhance the security of the system and to prevent the subscriber from being able to challenge the request he has made to the service provider, the IT means 21 (in the embodiment shown in Figure 1) include: software means for validating 21a orders given by the subscriber to the service provider, after detection of an encrypted acoustic signal issued by the card operated by the subscriber,software means for editing 21b of an acknowledgement of receipt of orders given to be sent to the subscriber.

Referring to Figures 4, 5 and 6, three embodiments are now described which allow the transmission of the acoustic identification signals 20 to the service provider's IT department 18 The same references on these figures have been used to designate the organs and means described in relation to Figure 1.

According to the first embodiment (Figure 4), the IT means 21 dependent on the IT services 18 of the service provider include means 200 for downloading into the multimedia terminal 16 a software to convert the sound file into bits, so that the signals from the multimedia terminal 16 are presented as a sequence of bits.

According to the second variant (Figure 5), the multimedia terminal 16 comprises means of conversion and transmission of 300 of the acoustic identification signals received by the microphone of the multimedia terminal, in the form of a sound file. This sound file is transmitted in particular after receipt of a signal issued by the IT services 18 of the service provider. This signal is issued after the telephone connection has been established between the terminal and the IT service. In the case of this variant the processing of the sound file and its transformation into a sequence of bits is carried out by the IT means 21 of the IT services 18 of the service provider.

In the third variant (Figure 6), the service provider provides the subscriber with a converter software (400) which the subscriber enters into its multimedia terminal 16 This converter software converts the acoustic signals received and transmitted by the microphone 17 of the multimedia terminal 16 into digital signals that can be transmitted remotely via the Internet-type computer network 15.

Claims

Process enabling the users (11) of an Internet-like computer network, having multimedia terminals (16) comprising a microphone (17) and connected to the Internet-like computer network (15), located at a distance from a service provider (12), to access securely and rapidly the services (30) that this service provider (12) offers to the users (11) of the Internet-like computer network, the said process comprising the following steps:
- the service provider (12) makes available to each of the users (11) of the Internet-like computer network who have subscribed to his services a card (10), in credit card format, customized with specific identifiers for each subscriber and for each card, the said card (10), in credit card format, sends short audio identification signals (20) of the DTMF type, at least partially encrypted, varying with each transaction, when it is activated (14) by the user (11) of the Internet-like computer network,

- the said audio identification signals (20) are received by the microphone (17) of the multimedia terminal (16) and are transmitted via the Internet-like computer network (15) to the computer facility (18) of the service provider,

- the signals transmitted and the identification data of the subscriber and of the card held (23) by the computer facility (18) are processed (24) and compared (25) electronically by the computer facility (18) of the service provider, so that, if there is a match, the subscriber (11) can be immediately put through to the services (30) of the service provider (12) .
Process according to Claim 1,
- the said card (10):
* additionally counts (105) the number of times C(p,n) (242) it is activated by the element (14),

* sends audio signals (20) representing the number of times C(p,n) (242) it has been activated,

* encrypts (103) the audio signals according to the number of times C(p,n) (242) it has been activated.

- the computer means (21) of the computer facility (18) which electronically process (24) and compare (25) the signals transmitted and the identification data of the customer and of the card held (23) by the computer facility (18) of the service provider:
* store (23) the number of times C(p,m) (246) the card has been activated during the last validated transaction,

* compare (245) the number of times C(p,n) (242) the card has been activated during the current transaction with the stored number of times C(p,m) (246),

* reject the current transaction if C(p,n) (242) is less than or equal to C(p,m) (246) and continue with the verification of the current transaction if C(p,n) (242) is greater than C(p,m) (246),

* recalculate (247) the electronic signals S'(p,n) (248) according to the identification data and the number of times C(p,n) (242) the card has been activated during the current transaction, then compare them (249) with the electronic signals S(p,n) (241) transmitted, so that, if there is a match, the subscriber (11) can be immediately put through to the services (30) of the service provider (12).
Process according to Claims 1 or 2, additionally comprising the following step:
- the subscriber (11) sends, by means of a keyboard (27) associated with the multimedia terminal (16) and/or with the card (10), a confidential code, after transmission to the computer facility (18) of the service provider (12), via the Internet-like computer network (15), this confidential code is processed and compared with the subscriber's personal confidential code held (23) by the computer facility (18) of the service provider (12).
Process according to Claims 1, 2 or 3, additionally comprising the following step:
- the orders issued by the subscriber (11) to the services (30) of the service provider (12) are validated by the subscriber by activation of the card (10) so that it sends an encrypted audio validation signal,

- the said validation signal is recorded by the computer facility (18) of the service provider (12), so that the subscriber (11) has validated, with an electronic signature, the order which he issued to the service provider (12).
Process according to Claims 1, 2, 3 or 4, additionally comprising the following steps:
- the audio identification signals (20), received by the microphone (17) of the multimedia terminal (16) and transmitted via the Internet-like computer network (15) to the computer facility (18) of the service provider (12), are transmitted in the form of a sound file.
Process according to Claims 1, 2, 3 or 4, additionally comprising the following steps:
- the computer facility (18) of the service provider (12) downloads conversion software to the multimedia terminal,

- the conversion software converts into a bit sequence the audio identification signals (20) received by the microphone (17) of the multimedia terminal (16),

- the bit sequence is transmitted, via the Internet-like computer network (15), to the computer facility (18) of the service provider (12),
so that the signals from the multimedia terminal appear in the form of a bit sequence.
Process according to Claims 1, 2, 3 or 4, additionally comprising the following steps:
- the service provider (12) makes available to each of the users (11) of the Internet-like computer network (15) who subscribe to his services (30) conversion software to be implemented in the multimedia terminal (16),

- the said audio identification signals (20) received by the microphone (17) of the multimedia terminal (16) are converted into bit sequences before being transmitted via the Internet-like computer network (15) to the computer facility (18) of the service provider.
System enabling the users of the Internet-like computer network (15) having multimedia terminals (16) comprising a microphone (17) and connected to the Internet-like computer network, and located at a distance from a service provider (12), to access securely and rapidly the services (30) that the said service provider (12) offers to the subscribed users (11), the said system comprising:
- a card (10), in credit card format, customized with specific identifiers for each card and for each subscriber, made available to the subscribers, the said card (10) comprising:
* means (13) of sending short audio identification signals (20) of the DTMF type, activated by the subscriber by means of an element (14) accessible from the outside of the card (10),

* encryption means (103) for encrypting at least partially and varying the audio signals (20) whenever the card (10) is activated (14),

- means (19) for transmitting the audio signals (20), located in the multimedia terminals (16), remotely transmitting the said audio signals (20) in the form of electronic signals via the Internet-like computer network (15),

- computer means (21), depending on the computer facilities (18) of the service provider (12), connected to the Internet-like computer network (15) and receiving the signals from the multimedia terminals (16), the said computer means (21) comprising:
* a database (23) containing the references of the cards (10) and of the subscribers (11) and their identification data,

* means of processing (24) and means of comparing (25) the electronic signals and the identification data contained in the database (23),

so that, if there is a match, the services (30) of the service provider (12) are immediately accessible to the subscribers (11).
System according to Claim 8,
- the said card (10) additionally comprising:
* an incremental counter (105) interconnected with the sending means (13) and the encryption means (103), and incremented by at least one unit whenever the card (10) is activated by the element (14),
so that the state of the incremental counter (105) is sent to the computer means (21) and the audio signals are encrypted according to the state of the incremental counter,

- the said computer means (21) additionally comprising:
* means (23) for storing the state C(p,m) (246) of the incremental counter (105) during the last validated operation,

* means for comparing (245) the state C(p,n) (242) of the incremental counter (105) sent during the current operation with the stored state C(p,m) (246) of the incremental counter,
so that the verification of the current transaction is rejected if C(p,n) (242) is less than or equal to C(p,m) (246) and is continued if C(p,n) (242) is strictly greater than (p,m) (246),

- the said means of processing (24) and the said means of comparing (25) the electronic signals and the identification data contained in the database comprising means for recalculating (247) the electronic signals according to the state C(p,n) (242) of the incremental counter (105) and the identification data and then for comparing them (249) with the electronic signals transmitted,
so that, if there is a match, the services (30) of the service provider (12) are immediately accessible to the subscribers (11).
System according to Claims 8 or 9, the said computer means (21) additionally comprising:
- second means of comparing (26) a confidential personal code of the subscriber contained in the database (23) with a confidential code sent by the subscriber by means of a keyboard (27) associated with the multimedia terminal (16) and/or with the card (10) and transmitted to the computer means (21) of the service provider (12) via the computer communication network (15).
System according to Claims 8, 9 or 10, the said computer means (21) additionally comprising:
- software means for validating (21a) the orders issued by the subscriber (11) to the service provider (12), after detection of an encrypted audio signal sent by the card (10) activated by the subscriber,

- software means for printing (21b) an acknowledgement of receipt of the issued orders, to be sent to the subscriber.
System according to Claims 8, 9, 10 or 11,
- the multimedia terminal comprising means of transmitting (300) the audio identification signals (20) received by the microphone (17) of the multimedia terminal (16), in the form of a sound file, via the Internet-like computer network (15), to the computer facility (18) of the service provider (12).
System according to Claims 8, 9, 10 or 11,
- the computer means (21), depending on the computer facilities (18) of the service provider (12), comprising:
* means of downloading (200) conversion software to the multimedia terminal (16), the said conversion software converting into a bit sequence the audio identification signals (20) received by the microphone (17) of the multimedia terminal (16),

* means of sending an order for the transmission of the bit sequence from the multimedia terminal (16) to the computer facilities (18) of the service provider, via the Internet-like computer network (15),

so that the signals from the multimedia terminal appear in the form of a bit sequence.
System according to Claims 8, 9, 10 or 11, comprising:
- conversion software to be implemented in the multimedia terminal (16), the said conversion software converting the audio signals (20) received and transmitted by the microphone (17) of the multimedia terminal into digital signals which can be remotely transmitted via the Internet-like computer network (15).