Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M15/00—Arrangements for metering, time-control or time indication ; Metering, charging or billing arrangements for voice wireline or wireless communications, e.g. VoIP
  • H04M15/47—Fraud detection or prevention means
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M15/00—Arrangements for metering, time-control or time indication ; Metering, charging or billing arrangements for voice wireline or wireless communications, e.g. VoIP
  • H04M15/28—Arrangements for metering, time-control or time indication ; Metering, charging or billing arrangements for voice wireline or wireless communications, e.g. VoIP with meter at substation or with calculation of charges at terminal
  • H04M15/30—Arrangements for metering, time-control or time indication ; Metering, charging or billing arrangements for voice wireline or wireless communications, e.g. VoIP with meter at substation or with calculation of charges at terminal the meter or calculation of charges not being controlled from an exchange
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M17/00—Prepayment of wireline communication systems, wireless communication systems or telephone systems
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
  • H04W4/24—Accounting or billing
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M2215/00—Metering arrangements; Time controlling arrangements; Time indicating arrangements
  • H04M2215/01—Details of billing arrangements
  • H04M2215/0148—Fraud detection or prevention means
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M2215/00—Metering arrangements; Time controlling arrangements; Time indicating arrangements
  • H04M2215/20—Technology dependant metering
  • H04M2215/2026—Wireless network, e.g. GSM, PCS, TACS
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M2215/00—Metering arrangements; Time controlling arrangements; Time indicating arrangements
  • H04M2215/32—Involving wireless systems

Definitions

• the invention relates to mobile telephones which are used with prepayment cards.
• a network of mobile telephones whether of the GSM or DCS type, corresponding respectively to the English acronyms "Global System for Mobiles” and “Digital Cellular System”, can be represented as comprising two parts:
• prepayment systems can be classified into three main categories depending on whether the prepayment functions are performed. (a) only by infrastructure,
• the invention aims to provide a system of category (c) in which all the service pricing operations are carried out by the mobile telephone and the memory card in a completely autonomous manner.
• a system in which 1 • infrastructure provides the mobile phone and the card with a cost advice better known by the acronym AoC for "Advice of Charge”.
• AoC Advanced of Charge
• the pricing to be applied is sent by the network infrastructure, which means that the latter must be provided for this purpose.
• the network infrastructure which means that the latter must be provided for this purpose.
• the pricing tables are housed in the network so that the pricing is frozen, which does not correspond to the wish of the network operator;
• the object of the invention is to guarantee that the user of the network inescapably discharges his communications by means of his prepaid card.
• the principle of the invention consists in proposing means making it possible to secure all the operations related to the management of the payment units, to the pricing, and to the debit proper, as well as means making it possible to trigger the authentication of the mobile and / or the card at times chosen by the operator.
• Another object of the invention is to provide means allowing interoperability between all mobiles, prepayment cards (cards with or without internal pricing table) or standard subscription cards.
• the mobile has a mechanism for selecting the operating mode appropriate to the type of card above.
• the mobile telephone and the card include specific functionalities for carrying out the prepayment application according to the invention
• the mobile phone / card unit independently determines the billing for the service
• the mobile phone / card unit manages the user's account
• - the payment unit counter is located in the card
• the invention relates to a mobile telephone system with a prepayment card in which a prepayment card is associated with a mobile telephone connected to a telephone network, characterized in that:
• the prepayment card comprises at least one microprocessor for performing cryptographic calculations with a view to encrypting and / or decrypting digital messages and a counter for payment units, containing the prepaid value,
• the mobile telephone includes at least one microprocessor for performing flow calculations depending on the characteristics of the telephone call and the telephone user as well as cryptographic calculations with a view to encrypting and / or decrypting digital messages, a device for recording and reading the prepayment card for exchanging said messages digital encrypted or not encrypted with said prepayment card and,
• each digital message recorded or read in the prepayment card is encrypted and / or decrypted using a cryptographic certificate contained in the digital message.
• the prepayment card further comprises a memory for recording the parameters of the pricing applied to the user.
• the mobile telephone and the prepayment card each further include a memory for this purpose.
• the mobile telephone and the prepayment card each further include a counter which is loaded with a random code supplied by the network and which is incremented by the same number of units at determined times.
• the invention also relates to a method for implementing the telephony system with prepayment card, characterized in that it comprises the following steps consisting in: (a) switching on the mobile telephone,
• step (b) recognize the presence or absence of a prepaid card connected to the mobile phone, and - go to step (c) if the card is absent or, - go to steps (d) and following in the case of the presence of the card, (c) operate the mobile telephone in the conventional manner in the absence of a prepaid card, (d) read the international identification number from the prepaid card the user of the prepayment card,
• FIG. 1 is a diagram showing the operations to be carried out with a view to obtaining the security of exchanges or transactions between the mobile telephone and the card
• - Figure 2 is a diagram showing the operations to be carried out with a view to recognizing and activating a prepayment card with an authorized mobile phone
• - Figure 3 is a diagram showing the operations to be carried out with a view to periodically authenticating the mobile telephone by the card
• FIG. 4 is a diagram showing the operations to be performed in order to choose pricing and debit the card.
• each figure has been divided into three vertical parts I, II and III separated by two broken lines 10 and 12 to indicate the three elements of the system, namely a network or infrastructure 14, a mobile telephone 16 and a prepaid card 18 which is often designated under the name SIM card, SIM being the acronym for Subscriber Identification Module, that is to say the user or subscriber identification module.
• SIM being the acronym for Subscriber Identification Module, that is to say the user or subscriber identification module.
• the operations indicated in each vertical part I, II or III are carried out by the corresponding element and the exchanges of information between the elements are materialized by horizontal arrows connecting the parts concerned by the exchange.
• the invention provides that these exchanges are carried out by implementing cryptographic methods according to the diagram in FIG. 1.
• the mobile telephone 16 develops a command 20 which, if it is critical for security, is encrypted by an operation 22 of cryptographic calculations.
• Some commands that are not security critical are not encrypted.
• the encrypted command or not is transmitted to the card 18.
• the encrypted command can contain a cryptographic certificate which allows its certification by the card 18.
• the command is transmitted without encryption (24) but, at the same time, a cryptographic certificate is transmitted (26) to the card and is recorded by the telephone in a file on the card called "mailbox".
• This certificate is used to perform cryptographic calculations so as to verify that it is an encrypted order (28) provided by the system. If the verification or certification is not valid (30), the card transmits an error signal (32) to the mobile telephone. In case of validation of the certification, the command is executed (34).
• the execution of the command gives rise to the elaboration of the response of the card (operation 36), response which is preferably encrypted (operation 38), especially if they are responses to critical commands such as aimed above with registration of a cryptographic certificate in the mailbox (operation 40).
• the response is transmitted to the mobile telephone (operation 42) while the cryptographic certificate is read by the mobile telephone in the mailbox (operation 44) to be used for cryptographic processing (verification) (operation 46) in the mobile telephone.
• access to the mailbox is carried out using conventional commands without security.
• securing bilateral mobile phone / card exchanges is based on a cryptographic calculation carried out by the transmitting party and verified by the receiving party, this calculation being carried out on each data transmission between the mobile telephone and the card .
• the invention provides an anti-replay mechanism which consists in introducing into the cryptographic calculation an arbitrary variable data which has a very low probability of resuming twice same value.
• This variable data can be obtained using a counter in the mobile telephone and the card, a counter which is updated independently by each party to the exchange and which is incremented by one with each cryptographic calculation.
• a counter value must be kept from one session to another, which implies that a given prepaid mobile telephone only works with a given prepaid card and has the drawback of being limiting.
• the invention uses a random number, called a "hike".
• a "hike" Preferably, for reasons of ease of implementation, use is made of the "random" which is found in the authentication request sent conventionally by the network.
• the mobile telephone and the card each record the value of "random" as the new initial value of the counter and each new command or certified response which must be exchanged between the mobile phone and card, each party will use the value of its counter as it is, then increment the same fixed number of units with each exchange of data or order. So that a mobile phone without prepayment will not be able to generate a registration request on the network with a prepayment card, the invention provides for deactivating certain functions of the card (operation 50, FIG. 2) after it has been turned on. voltage (operation 52) by the mobile phone and only activated by an authorized mobile phone. In order for the mobile phone to work with both prepaid cards and normal subscription cards, it is necessary to establish a mutual recognition procedure.
• any session begins with the recognition of the card by the mobile telephone (operation 54) by inspection of the configuration data of the card without particular security because a card which claims to be what it is not would be rejected during subsequent procedures.
• the system operates conventionally without prepayment (operation 60).
• the mobile telephone transmits to the card a read command (operation 62) of the international code of the subscriber better known by the acronym IMSI for International Mobile Subscriber Identification.
• This command to read the IMSI code is carried out with certification, certification which is validated or not by the card (operation 64). If the command to read the IMSI code is not validated, the card transmits an error signal to the mobile telephone (operation 66). Otherwise, 10 the card is fully activated and goes into the standby position (operation 72); it transmits its IMSI code (operation 70) to the mobile telephone which registers the subscriber to the network and waits for an authentication request (operation 72).
• the invention provides that, at the periodic request of the network, the mobile telephone preferably repeatedly proves à la carte and vice versa that it is empowered to operate a prepaid card.
• this verification of the authenticity of the mobile and / or of the card is triggered externally and unpredictably by the user by an existing procedure at the network level.
• the request for authentication of the card by the network is suitable as an external procedure which forces an interaction between the mobile and the card.
• the network transmits to the mobile telephone an authentication request (operation 80) which transmits it to the card (operation 84) after cryptographic calculation (operation 82) in an encrypted form with a cryptographic certificate as described below. above.
• the card performs a cryptographic calculation to authenticate the request (operation 86).
• the card If the certification is not validated (operation 88), the card transmits an error signal (operation 90) to the mobile telephone which retransmits it (operation 92) to the network. The latter then rejects the mobile phone (operation 94).
• the card transmits its response to the mobile phone (operation 96) which retransmits it to the network (operation 98).
• the pricing parameters are calculated by the card as a function of the characteristics of the call such as the number requested, the time, the location area, etc. These calculations are made from pricing tables stored in internal card files.
• the format of the parameters transmitted by the card to the mobile telephone and the manner of processing them by the latter can be of the AoC (Advance of Charge) type and are described in the operating standard of the GSM system.
• AoC Advanced of Charge
• the choice between one or the other pricing is made in particular by a secure detection of the presence of the pricing files in the card.
• the pricing parameters are processed by the mobile phone to determine how to charge the payment unit counter during the call. For example, a flat-rate debit at the line outlet, then a debit of payment units as a function of time. In this case, the periodicity with which the mobile comes to debit the meter in the card is defined by the pricing parameters. 12
• the credit remaining in the card's payment unit counter is checked by the mobile phone when the service is granted to the user, and then at each debit operation during the call.
• the decisions made by the mobile telephone as a function of the state of the meter are preferably in accordance with what is described for AoC in the GSM standard.
• the operations which are carried out for the choice of pricing and debit of units in the prepaid card will be described in relation to FIG. 4.
• the mobile telephone transmits the parameters of the call (operation 114) to the card, preferably in secure form by cryptographic calculation (operation 112) with a cryptographic certificate.
• the card verifies the certification (operation 116) and if this verification is valid, preferably transmits in secure form (operation 120) the pricing parameters as well as the remaining credit to the mobile phone.
• the mobile phone checks the remaining credit (operation 122) and authorizes or not the passage of the call to the network (operation 132).
• the connection is established (operation 124)
• the mobile telephone transmits the debit in payment units to the card in secure form as the telephone connection lasts (operation 126).
• the card responds with an acknowledgment of receipt, also secure, (operation 128), with a remaining amount of credit which is controlled by the mobile phone (operation 130).
• the mobile phone deducts 13
• operation 102 that the tariff is that of the network and allows the call to be made (operation 104).
• the network responds by transmitting the AoC parameters (operation 106) to the mobile phone with which the latter calculates the cost to be debited.
• operation 108 After checking the credit remaining in the card (operation 108), the mobile telephone authorizes or not the connection (operation 110) and performs with the card operations 126 and 128 to debit the card.
• FIG. 4 shows that all the debit commands and the acknowledgments of receipt are secured using the securing method described in relation to FIG. 1. By this method, it is ensured that the debit made in the card is authentic, honest and correctly made in a valid prepaid card.
• the acknowledgment of receipt may contain the updated value of the payment unit counter, thus avoiding the mobile to generate a separate order to know the value remaining in the counter.
• the mobile phone is capable of securely reading the value of the counter in the card by transmitting a zero flow command.
• the description which has just been made in relation to FIGS. 1 and 4 makes it possible to define the different stages of a method for implementing the mobile telephone system, these stages consisting in: (a) switching on the mobile telephone 16, (b) recognize the presence or absence of a prepaid card 18 connected to the mobile telephone, and - go to step (c) in the absence of the prepayment card or, 14
• Step (f) is triggered at the request of the network, during a request for registration to the network (connection) under the identification number read in the card and is preferably repeated from time to time during a connection session to renew the authentication and thus avoid a possible replacement of the module and / or the card during the session.
• Step (j) is also repeated to debit the payment unit counter so as to check the remaining credit.
• (A) perform cryptographic calculations on the digital message to be transmitted using a cryptographic key and / or a code (number) contained in a counter of the sender of the message,
• the step (f) of authentication of the mobile phone associated with the prepayment card comprises the following intermediate steps consisting in: (f ⁇ ) making an authentication request by the network on the mobile phone, (f 2 ) encrypting, in the mobile telephone, this authentication request, (f 3 ) transmit to the prepayment card a digital message containing this encrypted authentication request, (f 4 ) decipher, in the prepayment card, the digital message transmitted by the telephone mobile.
• (f 5 ) determine, in the prepayment card, whether the network authentication request transmitted by the mobile phone is valid or not, and - go to steps (f 6 ) and (f 7 ) in the absence of validation, go to steps (f g ) and (f g ) in the event of validation, (f 6 ) transmit an error signal to the network via the mobile phone, and (f 7 ) reject the mobile phone as a user of the network with the associated prepayment card, (f g ) transmitting to the network a validation signal via the mobile telephone, and (f g ) recognizing the mobile telephone as a user of the network with the associated prepayment card.
• the pricing is calculated by the card using internal tables contained in the card so that the pricing tables can be modified by personalization or by 17 remote administration. As a result, an operator can implement its own commercial pricing strategies by intervening at the card level.
• the prepayment card (18) comprises at least one microprocessor for performing cryptographic calculations of critical messages
• the mobile telephone (16) comprises at least one microprocessor for carrying out rate calculations according to telephone tariffs (AoC) as well as cryptographic calculations of critical messages
• AoC telephone tariffs
• the prepayment card further comprises a memory for recording the parameters of the pricing applied to the user, said parameters being read from the card by the mobile telephone.

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• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Business, Economics & Management (AREA)
• Accounting & Taxation (AREA)
• Computer Security & Cryptography (AREA)
• Meter Arrangements (AREA)
• Mobile Radio Communication Systems (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=9524317

Family Applications (1)

Country Status (8)

Cited By (1)

Families Citing this family (8)

Family Cites Families (5)

• 1998
  • 1998-03-20 FR FR9803482A patent/FR2776454B1/fr not_active Expired - Fee Related
• 1999
  • 1999-03-17 AU AU28413/99A patent/AU2841399A/en not_active Abandoned
  • 1999-03-17 BR BR9908904-1A patent/BR9908904A/pt not_active IP Right Cessation
  • 1999-03-17 CN CN 99804220 patent/CN1293861A/zh active Pending
  • 1999-03-17 EP EP99909020A patent/EP1064777A1/de not_active Withdrawn
  • 1999-03-17 WO PCT/FR1999/000603 patent/WO1999049647A1/fr not_active Application Discontinuation
  • 1999-03-17 JP JP2000538495A patent/JP2002508633A/ja active Pending
  • 1999-03-17 CA CA002323002A patent/CA2323002A1/fr not_active Abandoned

Non-Patent Citations (1)

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