Abstract:
Disclosed is an information protection system of an on-line service provider connected with customers&#39; telephones through a telephone network for protecting important personal information of the customers from being leaked by tapping the customers&#39; telephone lines, which includes an IVR system for collecting the customers&#39; information-input patterns based on the customers&#39; information-input signals received from the telephones and transmitting colored signals similar to the customers&#39; information-input signals through the telephone network to the customers&#39; telephone lines, and a control device for generating respective the colored signals similar to the customers&#39; information-input signals based on the customers&#39; information-input patterns, the colored signals being delivered to the IVR system. The IVR system transmits the colored signal to the customer&#39;s telephone line to scramble the customer&#39;s personal information being inputted. An echo canceller is provided to recover the customers&#39; personal information from the scrambled information. An information-input pattern analyzer is provided to analyze the information-input pattern data to determine the customers&#39; respective mean information-input patterns.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an information protection system of an on-line service provider connected with customers&#39; telephones through a telephone network, which provides a means for scrambling DTMF (Dial Tone Multiple Frequency) signals inputted by the customers so as to protect the important personal information of the customers from being leaked by tapping the customers telephone lines.  
         [0003]     2. Description of the Related Art  
         [0004]     DTMF tones are generated when pushing the keypad buttons of a touch-tone type telephone. DTMF is based on an international convention of technological standard. The keypad or dial pad of a telephone consists of 16 digit buttons indicating respectively ten numerals of 0 to 9 and other symbols of *, #, A, B, C, D, among which the symbols A, B, C, D do not usually appear in the commonly used telephone. The digits represent respectively certain composite frequencies each composed of one of the low frequencies of 697, 770, 852 and 941 Hz and one of the high frequencies of 1209, 1336, 1477 and 1633 Hz. For example, pushing the button indicating number 1 generates a mixed frequency composed of a low frequency 697 Hz and a high frequency 1209 Hz, which frequency is recognized by the switchboard as number 1.  
         [0005]     Referring to  FIG. 1  for illustrating a conventional interactive voice response (IVR) system, a customer contacts the IVR system  30  by a telephone  10  connected to a telephone network in order to receive on-line services. In this case, he must input citizen&#39;s registered number, bank account number, credit card number, various identification numbers, bank account secret number, on-line banking secret number, security card secret number, OPT secret number, and registered electronic key by generating DTMF signals through the telephone keypad. However, the conventional IVR system has an inherent drawback that the customer&#39;s private telephone line may be secretly tapped by another person to intercept the DTMF signals. The tapped DTMF signals are transmitted through an RF transceiver  91 ,  92  to be recorded by a recorder. The recorded DTMF signals are then analyzed by using a spectrum analyzer  93  to discover the values of the DTMF tones. Thus, the intercepted personal information may cause a great damage to the customer.  
       SUMMARY OF THE INVENTION  
       [0006]     It is an object of the present invention to provide an information protection system of an on-line service provider connected with customers&#39; telephones through a telephone network for protecting the important personal information of the customers from being leaked by tapping the customers&#39; telephone lines.  
         [0007]     According to an embodiment of the present invention, there is provided an information protection system of an on-line service provider connected with customers&#39; telephones through a telephone network for protecting important personal information of the customers from being leaked by tapping the customers&#39; telephone lines, which comprises an interactive voice response (IVR) system for collecting the customers&#39; information-input patterns based on the customers&#39; information-input signals received from the telephones and transmitting colored signals similar to the customers&#39; information-input signals through the telephone network to the customers&#39; telephone lines, and a control device for generating respective the colored signals similar to the customers&#39; information-input signals based on the customers&#39; information-input patterns, the colored signals being delivered to the IVR system.  
         [0008]     The IVR system further comprises a voice signal transmitter for transmitting the colored signals through the a telephone network to the customers&#39; telephone lines, a voice signal receiver for receiving the customers&#39; information-input signals generated by the telephones, an echo canceller for extracting the customers&#39; information-input signals from the output data of the voice signal receiver, an information-input pattern collector for collecting the customers&#39; information-input patterns, a data receiving and decoding device for receiving and decoding encoded colored signals inputted from the control device, and a main processor for controlling the voice signal transmitter, voice signal receiver, echo canceller, information-input pattern collector and data receiving and decoding device.  
         [0009]     The control device further comprises a data receiver for receiving the customers&#39; information-input pattern data from the IVR, an information-input pattern analyzer for analyzing the information-input pattern data to determine the customers&#39; respective mean information-input patterns, a colored signal generator for generating and storing the customers&#39; colored signals based on the mean information-input patterns, a data encoder for encoding the colored signals, a scheduler for determining the time and period fitting to deliver the encoded colored signals, and a data delivering part for delivering the encoded colored signals to the IVR in response to the output of the scheduler.  
         [0010]     Preferably, the information-input pattern collector distinguishes the customers&#39; information-input patterns by detecting tone duration indicating the time taken for each customer&#39;s pushing a telephone keypad button, pause-between-tone indicating the interval between successive pushes of buttons, or the strength of a received signal.  
         [0011]     The personal information includes citizen&#39;s registered number, bank account number, credit card number, various identification numbers, bank account secret number, on-line banking secret number, security card secret number, OTP (One Time Password), and registered electronic key.  
         [0012]     According to another embodiment of the present invention, there is provided an information protection method of an on-line service provider connected with customers&#39; telephone through a telephone network for protecting the important personal information of the customers from being leaked by tapping the customers&#39; telephone lines, which comprises the steps of storing the colored signals, searching the stored colored signals to retrieve the colored signal representing a customer presently using the on-line service, transmitting the colored signal of the customer to the customer&#39;s telephone line, requesting the customer to input his personal information to mix with the colored signal, the step of transmitting the colored signal being continued until completing the information input, receiving the mixed signal of the customer&#39;s information signal and the colored signal, and extracting the customer&#39;s information signal from the mixed signal.  
         [0013]     It is preferable that the information protection method includes the further steps of collecting and storing the customers&#39; information-input patterns based on the customers&#39; information-input signals received from the telephone, and generating respective colored signals similar to the customers&#39; information-input signals based on the customers&#39; information-input patterns, and storing the colored signals.  
         [0014]     It is preferable that the information protection method includes the further steps of determining the customers&#39; respective mean information-input patterns by analyzing the information-input pattern data, and generating and storing the customers&#39; respective colored signals based on the mean information-input patterns.  
         [0015]     Preferably, the personal information includes citizen&#39;s registered number, bank account number, credit card number, various identification numbers, bank account secret number, on-line banking secret number, security card secret number, OTP, and registered electronic key.  
         [0016]     The step of extracting the customer&#39;s information signal is achieved by echo cancellation.  
         [0017]     The mean information-input patterns preferably include tone duration indicating the time taken for a customer&#39;s pushing a telephone keypad button, pause-between-tone indicating the interval between successive pushes of buttons, and the strength of a received signal.  
         [0018]     The present invention will now be described more specifically with reference to the drawings attached only by way of example. 
     
    
     BRIEF DESCRIPTION OF THE ATTACHED DRAWINGS  
       [0019]      FIG. 1  is a schematic diagram for illustrating a conventional IVR system;  
         [0020]      FIG. 2  is a schematic diagram for illustrating the inventive information protection system of an on-line service provider connected with customers&#39; telephones through a telephone network;  
         [0021]      FIG. 3  is a block diagram for illustrating the construction of an information protection system according to an embodiment of the present invention;  
         [0022]      FIG. 4  is a flow chart for illustrating the signal flow of an information protection method according to an embodiment of the present invention;  
         [0023]      FIG. 5  is a schematic diagram for illustrating the process of inputting the customer&#39;s personal information and transmitting the corresponding colored signal according to the present invention;  
         [0024]      FIG. 6  is a graph for illustrating the waveform of a mixed signal f (3)  composed of a colored signal f (1)  and a customer information signal f (2) ; and  
         [0025]      FIG. 7  is a schematic diagram for illustrating the signal flow between a customer&#39;s telephone and an information protection system according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]     In the description, it is noted that the term “colored signal” is a signal that is generated by the inventive information protection system to be similar to a customer&#39;s information signal, and supplied to the customer&#39;s telephone line to mix with the customer&#39;s information signal during the customer&#39;s inputting his personal information so that the information gained by tapping the customer&#39;s telephone line can not be intelligible. Also noted is the term “echo”, which means returning of the colored signal transmitted from the IVR system to the customer&#39;s telephone line. Hence, the echo canceller is a device for eliminating the echoed colored signal from the mixed signal received by the IVR system.  
         [0027]     Referring to  FIG. 3 , an information protection system  300  according to an embodiment of the present invention includes an IVR system  310  and a control device  320 . The control device  320  may be connected with a plurality of IVR systems  310 . The IVR system  310  further includes a main processor  311 , voice signal transmitter  312 , voice signal receiver  313 , echo canceller  314 , information-input pattern collector  315 , data receiving and decoding device  316 , and interface circuit  317 . The control device  320  includes a data receiver  321 , information-input pattern analyzer  322 , colored signal generator  323 , data encoder  324 , scheduler  325 , and data delivering part  326 .  
         [0028]     The voice signal transmitter  312  transmits a service scenario voice file through a telephone network to the customer&#39;s telephone under the control of the main processor  311 , which voice file contains a menu and service content, and at this time also is transmitted the corresponding colored signal to the telephone.  
         [0029]     The voice signal receiver  313  receives all the information inputted by the customer, transferring it to the main processor  311 . The voice signal receiver  313  receives both voice signals and DTMF signals, but during the input of the customer&#39;s personal information the DTMF signals have priority to be received.  
         [0030]     The echo canceller  314  eliminates from the signal received by the voice signal receiver  313  the colored signal supplied by the IVR system  310 . In this case, all the signals transmitted through the voice signal transmitter  312  to a telephone network  200  are returned to the echo canceller  314 . Namely, the customer&#39;s personal information and the colored signal mixed therewith are all transferred to the echo canceller  314 . Thus eliminating the colored signal from the mixed signal received by the voice signal receiver  313 , there remains the customer&#39;s personal information transferred to the main processor  311 .  
         [0031]     The information-input pattern collector  315  obtains the information-input pattern data representing the characteristics of the customer&#39;s personal information outputted through the echo canceller  314 , which include the tone duration between the beginning and the ending of a DTMF tone and the pause between tones. The information-input pattern data of the customers are distinguished by the telephone numbers, delivered to the control device  320 .  
         [0032]     The data receiving and decoding device  316  receives and decodes the encoded colored signal from the control device  320 . The interface circuit  317  interfaces the IVR system  310  with a telephone network. Controlling the voice signal transmitter  312 , the voice signal receiver  313 , the echo canceller  314 , information-input pattern collector  315 , and the data receiving and decoding device  316 , the main processor  311  especially identifies the customer connected through a telephone network by the customer&#39;s telephone number, and retrieves the customer&#39;s colored signal transmitted through the voice signal transmitter  312  immediately before he inputs the personal information.  
         [0033]     The data receiver  321  organizes the customers&#39; information-input patterns collected through a single or multiple IVR systems into a database. The information-input pattern analyzer  322  analyzes a group of the customer&#39;s information-input patterns stored in the data receiver  321  to calculate the customer&#39;s mean information-input pattern with the most recent information-input pattern considered mainly.  
         [0034]     The colored signal generator  323  generates the corresponding colored signal transmitted through the voice signal transmitter  312  according to the customer&#39;s mean information-input pattern. The colored signal may be a pure DTMF tone or a mixture of a musical sound and a DTMF tone.  
         [0035]     The colored signal of the colored signal generator  323  is encoded by the data encoder  324 , delivered to the IVR system  310 . The scheduler  325  determines the time and period fitting for the control device  320  to deliver the colored signal to the IVR system  310 . The data delivering part  326  delivers the encoded colored signal to the IVR system  310  in response to the output of the scheduler  325 .  
         [0036]     Describing the operation of the inventive information protection system with reference to  FIG. 4 , at first the customer telephones the information protection system through a telephone network at step S 110 , and then the information protection system retrieves the colored signal corresponding to the customer at step S 120 , requests him to input his personal information at step S 130 , and begins to transmit at step S 140  the colored signal through a telephone network to the customer&#39;s telephone line before starting the input of the personal information and continues the transmission until the information input has been checked as finished at step S 160 .  
         [0037]     Then, at step S 170  the information protection system receives a mixed signal composed of the personal information signal and colored signal to extract the personal information signal at step S 180 . The personal information includes citizen&#39;s registered number, bank account number, credit card number, various identification numbers, bank account secret number, on-line banking secret number, security card secret number, OTP (One Time Password), and registered electronic key.  
         [0038]     When the customer has finished the input of his personal information, the information protection system calculates at step S 210  the customer&#39;s mean information-input pattern based on the customer&#39;s information-input patterns stored. The customer&#39;s mean information-input pattern is used at step S 220  to generate the colored signal of the customer stored.  
         [0039]     Hereinafter, the information protection method according to an embodiment of the present invention is described, divided into three parts of generating the colored signal, transmitting the colored signal, and recovering the customer&#39;s personal information.  
         [0040]     Generating the Colored Signal  
         [0041]     When a customer does financial transactions by telephoning the IVR system  310 , he must input the personal information such as bank account number and password. At this time the IVR system  310  collects the customer&#39;s information-input pattern that is the manner in which he inputs his personal information. For example, the citizen&#39;s registered number is usually memorized, thus being inputted quickly without an error, while the information such as a password is inputted slowly with a confirmatory act. The information-input pattern not only varies with the kind of the information, but also with the age of the customer. Based on this information-input pattern is generated a corresponding colored signal f (1)  transmitted through the IVR system.  
         [0042]     The values of the information-input patterns differ from each other according to the customers, and therefore the IVR  310  must also supply different colored signals f (1) . To this end, the information-input patterns of the customers are organized into a database, based on which a colored signal f (1)  similar to each customer&#39;s information-input pattern is generated so that the mixed signal f (3)  intercepted cannot be analyzed by the interceptor to distinguish the customer&#39;s personal information.  
         [0043]     The specific examples of the information-input pattern include tone duration indicating the time taken for a customer&#39;s pushing a telephone keypad button, pause-between-tone indicating the interval between successive pushes of buttons, and the strength of a received signal. The collection of a customer&#39;s information-input pattern is not accomplished by once, but in order to update the customer&#39;s information-input pattern is performed whenever the customer inputs his personal information by contacting the IVR system.  
         [0044]     The information-input pattern collector  315  of the IVR  310  distinguishes each customer&#39;s information-input pattern data according his telephone number, transferred to the control device  320 . The data receiver  321  of the control device  320  organizes the customer&#39;s information-input data into a database.  
         [0045]     The information-input pattern analyzer  322  analyzes the information-input patterns of a customer stored in the data receiver  321  to retrieve the information-input pattern most similar to the most recent one, which is employed by the colored signal generator  323  to generate a corresponding colored signal encoded by the data encoder  324 . Then the scheduler  325  determines the time and period fitting to deliver the encoded colored signal through the data delivering part  326  to the IVR system  310 , where the data receiving and decoding device  316  decodes the encoded colored signal, transmitting it by the main processor  311  through the voice signal transmitter  312  to a telephone network  200 .  
         [0046]     Transmitting the Colored Signal  
         [0047]     The IVR system  310  has a service representative telephone number to enable a customer to receive an on-line service from the service provider at any place connected with a telephone network. The IVR system  310  is connected through a digital line T 1  or E 1  to a telephone network  200 , which is divided into transmitting and receiving parts consisting of four wires connecting the IVR system  310  and a telephone network  200 . The two of the four wires are respectively used for the IVR system  310  to receive the customer&#39;s voice signal and personal information data while the other two for the IVR  310  to transmit the service&#39;s voice signal and information data to the customer.  
         [0048]     In order to receive an on-line service, when a customer telephones the IVR system of an on-line service provider, the IVR system first provides a ready-made voice menu for the customer to select a service by pushing DTMF tone buttons. In addition, the IVR system requires the customer to input identifying information such as the citizen&#39;s registered number, bank account number, membership number, password and security card number by pushing the DTMF buttons.  
         [0049]     While the customer inputs the personal information by the personal information, the IVR system  310  also transmits the corresponding colored signal through a telephone network  200 , as shown in  FIG. 5 . The colored signal is selected from those stored in the IVR system  310 , representing the customer presently contacting through a telephone network. Referring to  FIG. 5 , the customer&#39;s personal information is represented by f (2) , the colored signal by f (1) , and the mixed signal by f (3) . Thus, if the line of the customer&#39;s telephone is tapped, there is intercepted the mixed signal f (3)  of the colored signal f (1)  and the customer&#39;s personal information signal f (2) that is unintelligible.  FIG. 6  illustrates the waveforms of the colored signal f (1) , customer&#39;s information signal f (2)  and the mixed signal f (3) .  
         [0050]     Extracting the Customer&#39;s Information Signal from the Mixed Signal  
         [0051]     As described above, transmitting the colored signal through a telephone network  200  results in the mixed signal of the colored signal and the customer&#39;s personal information signal existing in the line between the customer&#39;s telephone  100  and a telephone network  200 .  
         [0052]     Referring to  FIG. 7  for illustrating the form of the mixed signal of the colored signal and the customer&#39;s information signal existing in the customer&#39;s telephone line, the customer&#39;s telephone generates the personal information signal consisting of 1, 2, 3 and 4, which is mixed with the colored signal consisting of DTMF tones 5, 9, 6, 0, 7, 3 and 8 so as to produce the mixed DTMF tone signal consisting of 1, 5, 9, 6, 0, 2, 3, 7, 4, 3 and 8 in the telephone line between the customer&#39;s telephone  100  and a telephone network  200  that is unintelligible.  
         [0053]     Hence, the IVR system  310  must recover the customer&#39;s personal information from the mixed signal coming through a telephone network. To this end, the IVR system  310  employs the echo cancellation technology to extract the customer&#39;s personal information form the mixed signal. The echo cancellation technology employs G.168 technology established as standard by ITU-T (International Telecommunications Union-Telecommunication Standardization Sector). The echo canceller  314  of the IVR system  310  performs echo cancellation to eliminate the colored signal transmitted by the voice signal transmitter  312  from the mixed signal received through the voice signal receiver  313 , thus recovering the customer&#39;s pure personal information transferred to the main processor  311 . Referring to  FIG. 5 , the IVR system  310  of the information protection system  300  transmits the colored signal f (1) , and then performs echo cancellation to recover the customer&#39;s personal information signal f (2)  of 1, 2, 3 and 4 from the mixed signal f (3) of the colored signal f (1)  and the customer&#39;s personal information signal f (2)  that is received.  
         [0054]     Although the information protection system according to the embodiment described above comprises separate IVR system and control device, it will be readily appreciated by those skilled in this art that the IVR system can be designed to include all the elements of the control device. According to the present invention, even an on-line guide employed by an on-line service provider cannot catch the personal information of a customer because the colored signal scrambles the personal information during its input.  
         [0055]     While the present invention has been described in connection with specific embodiments accompanied by the attached drawings, it will be readily apparent to those skilled in the art that various changes and modifications may be made thereto without departing the gist of the present invention.