Method and system for ensuring the security of fax transmission using an identifying card

Method used to transmit a fax in a reliable manner between at least two persons, one (the sender) (11 FIG. 2) sending the fax (162 FIG. 2) by means of a first fax machine (161 FIG. 2) associated with first telephone equipment (16 FIG. 2), and particularly a first terminal emulating this function, the other (the receiver) (111 FIG. 2) receiving, the fax (262 FIG. 2) by means of a second fax machine (261 FIG. 2) associated with second telephone equipment (116 FIG. 2), and particularly a second terminal emulating, this function, the faxes (162) being routed through a communications network (15) via a center (30) for management of faxes exchanged between the sender (11) and the receiver (111),

• the fax management center (30) provides the sender (11 FIG. 2) and the receiver (111 FIG. 2) with a card (10, 110 FIG. 2), the same size as a credit card, personalized by identifiers-specific to each sender (11 FIG. 2) and each receiver (111 FIG. 2),
• the said card (10, 110 FIG. 2) emits short DTMF type acoustic identification signals (20, 120 FIG. 2), at least partly encrypted and varying with each operation, when it is activated (14) by the sender (11 FIG. 2) or the receiver (111 FIG. 2) through an element (14 FIG. 1),
• the said card (10, 110 FIG. 2):
• also counts (105) the number of times C(p,n) (242) that it has been used and activated by the element (14), wherein C(p,n) takes account of all activations, including activations at a wrong time, p2 emits acoustic signals (20, 120) representing the number of times C(p,n) (242) that it has been used and activated by the element (14),
• encrypts (103) acoustic identification signals (20, 120) into a function S(p,n) as a function of the number of times C(p,n) (242) that it has been used and activated by the element (14),
• the said acoustic identification signals (20, 120) are received by a microphone (17, 117 FIG. 2) of the telephone equipment, and particularly a terminal emulating this function, and are converted into electronic signals before being transmitted through the communications network (15) to the computer service (18) in the fax management center (30),
• the said method comprises the following steps:
• the sender (11 FIG. 2) activates (14 FIG. 2) the sender card such that it sends acoustic identification signals (20 FIG. 2),
• the acoustic identification signals (20 FIG. 2) received by the microphone (17 FIG. 2) on the first telephone equipment (16 FIG. 2) and transmitted in the form of said electronic signals through the communications network (15 FIG. 2) and the specific identifiers held by the computer service (18 FIG. 2) are processed (24 FIG. 2) and electronically compared (25 FIG. 2) by the computer service (18 FIG. 2) in the fax management center (30 FIG. 2), by computer means (21) which:
• store (230) the number of times C(p,n) (246) that the sender card (10) has been used at the time of the last validated operation,
• compare (245) the number of times C(p,n) (242) that the sender card (10) has been used at the time of the current operation, with the memorized number of times C(p,m) (246),
• refuse the current operation if C(p,n) (242) is less than or equal to C(p,m) (246) and continue verifying the current operation if C(p,n) (242) is greater than C(p,m) (246),
• recalculate (239) the acoustic identification signals (20) into a function S′(p,n) as a function the number of tines C(p,n) (242) that the sender card (10) has been used and activated by the element (14) at the time of the current operation and as a function of said specific identifiers,
• then compare (249) S′(p,n) with the transmitted electronic signals S(p,n) (241),
• such that if the results conform the fax (162 FIG. 2) sent by the sender (11 FIG. 2) by means of the said first fax machine (161 FIG. 2) is stored by the fax management center (30),
• the receiver (111 FIG. 2) activates the receiver card (110 FIG. 2) so that it emits acoustic identification signals (120 FIG. 2),
• the acoustic identification signals (120 FIG. 2) received by the microphone (117 FIG. 2) on the said second telephone equipment (16 FIG. 2) and transmitted in the form of electronic signals through the communications network (15 FIG. 2) and the specific identifiers held by the computer service (18 FIG. 2) are processed (24 FIG. 2) and electronically compared (25 FIG. 2) by the computer service (18 FIG. 2) in the fax management center (30 FIG. 2), by computer means which:
• store (230) the number of times C(p,m) (246) that the receiver card has been used at the time of the last validated operation,
• compare (245) the number of times C(p,n) (242) that the receiver card has been used at the time of the current operation, with the memorized number of times C(p,m) (246),
• refuse the current operation if C(p,n) (242) is less than or equal to C(p,m) (246) and continue verifying the current operation if C(p,n) (242) is greater than C(p,m) (246),
• recalculate (239) the acoustic identification signals (120) into a function S′(p,n) as a function the number of times C(p,n) (242) that the receiver card has been used and activated by the element (14) at the time of the current operation and as a function of said specific identifiers,
• then compare (249) S′(p,n) with the transmitted electronic signals S(p,n) (241),
• such that if the results are conform, the fax management center (30) sends the fax (262 FIG. 2) stored by the fax management center to the second fax machine (261 FIG. 2) and the receiver (111 FIG. 2).

System used to transmit a fax (162 FIG. 1) in a reliable manner between a sender sending the fax and at least one receiver (11 FIG. 1) receiving, the fax using a fax-machine (161 FIG. 1) associated with telephone equipment (16 FIG. 1) (or a terminal emulating this function), the faxes being routed between the sender and receiver through a communications network (15) via a fax management center (30),

• the said system being such that it comprises:
• at least one card (10 FIG. 1) for use by the receiver (11 FIG. 1), the same size as a credit card, personalized by identifiers specific to each card and to each receiver, the said card (10 FIG. 1) comprising:
• emission means (13 FIG. 1) of emitting, short DTMF type acoustic identification signals (20 FIG. 1), activated (14 FIG. 1) by the receiver (11 FIG. 1) using an element (14 FIG. 1) accessible from the outside of the card (10 FIG. 1),
• an incremental counter (105), interconnected to the emission means (13) and an encryption means (103), which are incremented by at least one unit each time that the card (10) is activated by element (14) and said card (10 FIG. 1) has emitted said acoustic identification signals (20 FIG. 1),
• an encryption means (103) interconnected with the incremental counter (105) and the emission means (13) for encrypting at least partially and varying the acoustic identification signals (20 FIG. 1) into a function S(p,n) as a function of said number of times C(p,n) (242) the card (10 FIG. 1) has been used and activated by element (14), wherein C(p,n) takes account of all activations, including activations at a wrong time,
• telephone equipment (16 FIG. 1) (or any terminal emulating this function) comprising a microphone (17 FIG. 1) designed to receive and transform received acoustic identification signals into electronic signals transmitted through the communications network (15) to the computer services (18) in the fax management center (30),
• computer means (21) associated with the computer services (18) in the fax management center (30) connected to the communications network (15), the said computer means (21), comprising:
• a database (23) containing the references of each receiver card and each receiver and said specific identifiers,
• a means of memorizing (23, 230) the number of times C(p,n) (246) that the receiver card has been used at the time of the last validated operation,
• a means of comparing (245) the number of times C(p,n) (242) that the receiver card has been used at the time of the current operation, with the memorized number of times C(p,m) (246),
• such that the check on the current operation is refused if C(p,n) (242) is less than or equal to C(p,m) (246) and is continued if C(p,n) (242) is greater than C(p,m) (246),
• a means for recalculating (239) said acoustic identification signals (20 FIG. 1) into a function S′(p,n) (248) as a function of the number of times C(p,n) (242) said card has been used and activated by the element (14) at the time of the current operation and as a function of said specific identifiers,
• a means for comparing S′(p,n) to S(p,n)
• means (28) of sending a fax, which, if the results conform, send the fax (162 FIG. 1) addressed to the receiver (11 FIG. 1) by the sender to the fax machine (161 FIG. 1) belonging to the receiver (11 FIG. 1).

System used to transmit a fax in a reliable manner between at least two persons, one (the sender) (11 FIG. 2) sending the fax (162 FIG. 2) by means of a first fax machine (161 FIG. 2) associated with first telephone equipment (16 FIG. 2), and particularly a first terminal emulating this function, the other (the receiver) (111 FIG. 2) receiving the fax on a second fax machine (261 FIG. 2) associated with second telephone equipment (116 FIG. 2), and particularly a second terminal emulating this fiction, the faxes being routed through a communications network (15) via a fax management center (30) managing faxes exchanged between sender and receiver, the said system being such that it comprises:

• at least two cards (10, 110 FIG. 2), one for use by the receiver (111 FIG. 2) (the receiver card), the other for use by the sender (11 FIG. 2) (the sender card) the same size as a credit card, personalized by identifiers specific to each card and to each sender or receiver;
• the said receiver card or sender card comprising:
• an emission means (13, 113 FIG. 2) of emitting short DTMF type acoustic signals (20, 120 FIG. 2), activated by the sender or the receiver, by means of an element (14, 114 FIG. 2) accessible from the outside of the receiver card or sender card,
• an incremental counter (105), interconnected to the emission means (13) and an encryption means (103), which are incremented by at least one unit each time that the card (10) is activated by element (14) and said card (10 FIG. 1) has emitted said acoustic identification signals (20 FIG. 1),
• an encrypting means (103) interconnected with the incremental counter (105) and the emission means (13) for encrypting at least partially and varying the acoustic identification signals (20 FIG. 1) into a function S(p,n) as a function of said number of times C(p,n) (242) the card (10 FIG. 1) has been used and activated by element (14), wherein C(p,n) takes account of all activations, including activations at a wrong time,
• the said system being such that:
• the first and second telephone equipment (16, 116 FIG. 2), particularly a first or second terminal emulating this function, comprise a microphone (17, 117 FIG. 2) designed to receive and transform the received acoustic identification signals into electronic signals transmitted through the communications network (15) to computer services (18) in the fax management center (30),
• computer means (21) associated with the computer services (18) in the fax management center (30), connected to the communications network (15), the said computer means (21) comprising:
• a database (23) containing the references of each receiver card or sender card and each receiver or sender and said specific identifiers,
• a means of memorizing (23, 230) respectively the number of times C(p,n) (246) that the receiver card or the sender card has been used at the time of the last validated operation,
• a means of comparing (245) respectively the number of times C(p,n,) (242) that the receiver card or the sender card has been used at the time of the current operation, with respectively the memorized number of times C(p,m) (246),
• such that the check on the current operation of the receiver card or the sender card is refused if respectively C(p,n) (242) is less than or equal to C(p,m) (246) and is continued if respectively C(p,n) (242) is greater than C(p,n) (246),
• a means for recalculating (239) respectively said acoustic identification signals (20, 120 FIG. 2) emitted respectively by the receiver card and the sender card into a function S′(p,n) (248) as a function of the number of times C(p,n) (242) said receiver card and said sender card has been respectively used and activated by the element (14) at the time of the current operation and as a function of said specific identifiers,
• a means for comparing respectively S′(p,n) to S(p,n) and for validating respectively the sender's card identifiers and the receiver's card identifiers
• storage means (21a FIG. 2) storing the fax sent by the first fax machine, if the sender's card identifiers are validated,
• fax sending means (28 FIG. 2) sending the fax to the fax machine (261 FIG. 2) belonging to receiver (111 FIG. 2), if the receiver's card identifiers are validated.