Method and apparatus for the secure communication of data
First Claim
1. A device for generating a set of tones encoded with data, each tone in the set being separated by an interdigit period, the device including:
- memory storing encoding information relating to alterable tone characteristic values and storing corresponding data items; and
an encoding generator electrically coupled to said memory, said encoding generator generating a set of tones encoded with said alterable tone characteristic values in response to said encoding information and said data items.
3 Assignments
0 Petitions
Accused Products
Abstract
An auto-dialer suitable for use as a smart card capable of being acoustically coupled to a telephone and being reprogrammed in response to acoustic signals. The programming and other features of the auto-dialer can be enabled or disabled by the auto-dialer in response to persecuted signals, e.g., a string of DTMF tones. Encryption of calling card and other data into destination telephone numbers is achieved by selectively altering persecuted characteristics of a DTMF tone sequence, such as the duration of tones, the period of silence between tones and the twist between Lo-band and Hi-band tones of DTMF tone pairs in a DTMF tone sequence representing a telephone number. The encryption of data into the telephone number does not affect the ability of standard telephone switching circuitry to recognize the destination number. However, information encrypted into the DTMF signals is undetectable to standard telephone switching circuitry because it is encrypted using DTMF signal characteristics not normally used to represent data. The auto-dialer has a system clock used to drive a pseudo random number generator used in various data security schemes. Calibration features permit the calibration of the audio output and system clock with adjustments being made via the acoustic programming of the auto-dialer with various calibration factors.
328 Citations
112 Claims
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1. A device for generating a set of tones encoded with data, each tone in the set being separated by an interdigit period, the device including:
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memory storing encoding information relating to alterable tone characteristic values and storing corresponding data items; and an encoding generator electrically coupled to said memory, said encoding generator generating a set of tones encoded with said alterable tone characteristic values in response to said encoding information and said data items. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53)
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54. A device -for generating DTMF tone pairs encoded with data, the device comprising:
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memory storing information elements and non-frequency DTMF tone pair characteristic values, each one of the information elements being associated with one of the non-frequency DTMF tone pair characteristic values; a signal generator controllably generating DTMF tone pairs with non-frequency DTMF tone pair characteristic values corresponding to ones of said values stored in said memory; and a processor coupled to said memory and said signal generator, said processor controlling the signal generator to generate said DTMF tone pairs as a function of said stored values. - View Dependent Claims (55, 56, 57, 58)
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59. A device for decoding data encoded into a set of tones having non-frequency tone characteristic values representing encoded information, said device comprising:
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a data table storing a plurality of non-frequency tone characteristic values and a data element associated with each of the stored non-frequency tone characteristic values; a detector detecting the non-frequency tone characteristic values representing the encoded information; and a processor coupled to said data table and said detector, said processor decoding said encoded information as a function of the data stored in the data table and the detected non-frequency tone characteristic values. - View Dependent Claims (60, 61, 62, 63, 64, 65, 66, 67, 68)
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69. A device for generating a series of tone signals providing non-frequency modulation of data, each tone signal including simultaneously asserted first and second tones, the device comprising:
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a first tone generator circuit generating a first tone; a second tone generator circuit generating a second tone; a first amplification circuit coupled to said first tone generator circuit amplifying the first tone; a second amplification circuit coupled to the second tone generator circuit amplifying the second tone, said first and second amplification circuits operating independently to provide non-frequency modulation of data; a control circuit controlling the first and second tone generator circuits and the first and second amplification circuits to generate a series of first and second tones; and an output circuit coupled to said first and second amplification circuits combining the series of first and second tones to generate a series of tone signals.
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70. A device for generating a series of tone signals providing non-frequency modulation of data, each tone signal including simultaneously asserted first and second tones, the device comprising:
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a first tone generator circuit generating a first tone; a second tone generator circuit generating a second tone; a first amplification circuit electrically coupled to said first tone generator circuit, said first amplification circuit amplifying the first tone; a second amplification circuit electrically coupled to the second tone generator circuit, said second amplification circuit amplifying the second tone, said first and second amplification circuits operating independently to provide non-frequency modulation of data; a control circuit electrically coupled to said first and second amplification circuits and said first and second generator circuits, said control circuit controlling the first and second tone generator circuits and the first and second amplification circuits to generate a series of first and second tones; an output circuit coupled to said first and second amplification circuits, said output circuit combining the series of first and second tones to generate a series of tone signals; memory storing a plurality of twist levels, each twist level representing the difference of the amplification of a first tone and a second tone of a tone signal; and wherein the control circuit includes a processor coupled to said memory and said first and second amplification circuits, said processor accessing said memory and controlling the amplification levels of said first and second amplification circuits to introduce into the tone signals being generated the level of twist stored in the memory for the tone signal being generated. - View Dependent Claims (71)
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72. A device for generating a series of tone signals providing non-frequency modulation of data, each tone signal including simultaneously asserted first and second tones, the device comprising:
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a first tone generator circuit generating a first tone; a second tone generator circuit generating a second tone; a first amplification circuit electrically coupled to said first tone generator circuit, said first amplification circuit amplifying the first tone; a second amplification circuit electrically coupled to the second tone generator circuit, said second amplification circuit amplifying the second tone, said first and second amplification circuits operating independently to provide non-frequency modulation of data; a control circuit electrically coupled to said first and second amplification circuits and said first and second generator circuits, said control circuit controlling the first and second tone generator circuits and the first and second amplification circuits to generate a series of first and second tones; an output circuit coupled to said first and second amplification circuits, said output circuit combining the series of first and second tones to generate a series of tone signals; a speaker coupled to the output circuit converting the series of tone signals into acoustic signals; and a microphone located in proximity to the speaker and coupled to the control circuit converting the acoustic signals into an electrical feedback signal, wherein the series of tone signals are electrical signals. - View Dependent Claims (73)
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74. A device for generating and dynamically encrypting data into a set of tones, said device comprising:
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memory storing data, information relating to alterable tone characteristic values and a plurality of encryption methods, each of said plurality of encryption methods being valid for use at different times; an encryptor electrically coupled to said memory, said encryptor selecting which of said encryption methods is valid for use and using said valid encryption method to associate each of said alterable tone characteristic values with a data item; and a tone generator in electrical communication with said encryptor. - View Dependent Claims (75, 76, 77)
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78. A device for generating a set of tones encoded with data, each tone in the set being separated by an interdigit period, the device including:
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memory storing encoding information relating to alterable out-of-band tone characteristic values and storing corresponding data items; and an encoding generator electrically coupled to said memory, said encoding generator generating a set of tones encoded with said alterable out-of-band tone characteristic values in response to said encoding information and said data items to provide out-of-band transmission of said data items. - View Dependent Claims (79)
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80. A method of generating a set of tones encrypted with data, wherein the tones are separated by interdigit periods, said method comprising the steps of:
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storing information in a data table, the information relating to a set of N variations of a first tone characteristic value, wherein the first tone characteristic value can be selectively altered and wherein N is a positive integer; and generating, as a function of the stored information and the data to be encrypted, the set of tones wherein the first tone characteristic value is varied, as a function of the data to be encrypted, with the generation of each tone, to correspond to one of the set of N variations of the first tone characteristic value. - View Dependent Claims (81, 82, 83, 84, 85, 86, 87, 88)
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89. A method of generating a set of tones encoded with data, comprising the steps of:
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storing in a data table a plurality of information elements and a plurality of alterable tone characteristic values, each one of the information elements being associated with one of the plurality of alterable tone characteristic values; using the data to be encoded to obtain the alterable tone characteristic value associated with the data to be encoded from the data table; and generating, as a function of the alterable tone characteristic value obtained from the data table, a set of tones. - View Dependent Claims (90, 91, 92, 93, 94, 95, 96, 97)
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98. A method of generating an audio DTMF signal providing non-frequency modulation of data, comprising the steps of:
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generating a Lo-frequency tone signal; amplifying the Lo-frequency tone signal to create a Lo-frequency tone signal having a first power level; generating a Hi-frequency tone signal; amplifying the Hi-frequency tone signal separately from said Lo-frequency tone signal to generate a Hi-tone signal having a second power level that differs from the first power level to provide non-frequency modulation of data; combining the Lo-frequency and Hi-frequency tone signals to form a tone pair; amplifying the tone pair; and supplying the amplified tone pair to a speaker to generate said audio DTMF signal. - View Dependent Claims (99, 100, 101, 102, 103, 104, 105, 106, 107, 108)
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109. A method of dynamically encrypting data into a set of tones, said method comprising the steps of:
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storing data items, information relating to alterable tone characteristic values and a plurality of encryption methods, each of said plurality of encryption methods being valid for use at different times; determining which of said plurality of encryption methods is valid for use; using said valid encryption method to associate each of said alterable tone characteristic values with a data item; and generating a set of tones as a function of the alterable tone characteristic values associated with each data item to be encrypted. - View Dependent Claims (110, 111, 112)
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Specification