Abstract:
Provided is a personal authentication system that performs an online personal authentication and, more particularly, to a personal identification and anti-theft system and method, which provide, to a user terminal unit, an authentication key (C) issued upon request for a personal authentication and generate an authentication association value corresponding to the authentication key (C) by a disposable random key in performing the personal authentication. Therefore, even if the authentication key (C) is lost or deprived, the present invention can prevent an appropriation of the key and achieve a safe personal authentication, thereby preventing illegal use of the personal authentication and the authentication key (C).

Description:
BACKGROUND 
       [0001]    The present invention relates, in general, to a user authentication system for authenticating a user online and, more particularly, to a system and method for user authentication and identity theft prevention, in which user authentication is performed by providing a user terminal unit with an authentication key C, issued upon receiving a request for user authentication, and by generating an authentication-related value corresponding to the authentication key C using a one-time random key, whereby even if the authentication key C is leaked or stolen, the fraudulent use of the authentication key C is prevented and user authentication is safely performed. 
         [0002]    Currently, Internet technology has been developed such that a cloud computing environment, in which access to the Internet is possible anywhere anytime, is constructed. With the construction of a cloud computing environment, the use of credit information is increasing online. Such credit information is widely used in various fields such as signing up online, the purchase and sale of goods, economic activities through financial institutions, and the like. 
         [0003]    Accordingly, hackers steal credit information, which is being used online, and monetarily harm individuals by fraudulently using the stolen credit information. 
         [0004]    Therefore, in order to prevent hackers from stealing personal credit information, Internet systems employ various authentication systems. These authentication systems mainly use a user authentication system for authenticating a user who wants to use an arbitrary service on the Internet (here, user authentication may be called “user identification”, “personal authentication”, or the like). 
         [0005]    Generally, in a user authentication system, in order to check whether a user is an approved user who is permitted to use a corresponding service, that is, in order to authenticate the user when the user requests a service such as registration of the user, a change of user information, payment, or money transfer, user information authentication is first performed by sending user information, input by the user, to an existing authentication system (hereinafter, referred to as a “legacy authentication system”) such as a mobile communication system, a credit assessment system, or a public certification system, in which user information corresponding to the user has been registered in advance, and by comparing the user information input by the user with the registered user information, a user authentication message, which includes an authentication number, is sent to the mobile communication terminal of the user whose information has been authenticated, the authentication number is input by the user through a user&#39;s computer within a certain time period, and whether the input authentication number is the same as the issued authentication number is checked, whereby user authentication is performed. Generally, according to the method of authenticating a user, the user information, input by the user, may be the social security number of the user, or may be the card number, card validation code (CVC), or expiry date of a credit card owned by the user. 
         [0006]    As described above, because the conventional user authentication system requires the input of important personal information and credit information of a user, such as a social security number, a credit card number, and the like, it is problematic in that credit information, such as a user&#39;s social security number, may be leaked through memory hacking or the like. 
         [0007]    Also, the conventional user authentication system is problematic in that an authentication message, including an authentication number for user authentication, may be stolen and illegally used by a third party. 
         [0008]    In order to prevent these problems, Korean Patent Application Publication No. 10-2013-0084727 (hereinafter, referred to as “prior patent 1”) and Korean Patent Application Publication No. 10-2014-0003353 (hereinafter, referred to as “prior patent 2”) disclose a method in which a user selects, in advance, digits to be used from among the digits of an authentication number, included in a received authentication message, and the user inputs only values corresponding to the digits selected in advance, whereby security is improved. 
         [0009]    Also, in order to solve the problem with the above-described conventional user authentication system, Korean Patent No. 10-1321829 (hereinafter, referred to as “prior patent 3”) discloses a method in which a user confirmation message that contains a website URL is sent before a user authentication message is sent, a password is input by a user after the user is prompted to access the URL in the user confirmation message, and the user authentication message is sent only when the input password is the same as a previously registered password. 
         [0010]    However, the prior patents merely have a difference therebetween as to the method of inputting an authentication number, but still employ a method using mobile messages. Accordingly, they are vulnerable to memory hacking and interception of mobile messages, such as SMS, LMS, MMS, and the like. 
         [0011]    Therefore, the prior patents are also problematic in that an authentication number may be hacked and illegally used by a third party. 
         [0012]    Furthermore, because the prior patent 3 sends a text message that contains a URL, there is concern that a user may mistake the text message as SMiShing, and when the user mistakes the text message as SMiShing and deletes it, the user may experience inconvenience or may not receive a desired service. 
       SUMMARY OF THE INVENTION 
       [0013]    Accordingly, an object of the present invention is to provide a system and method for user authentication and identity theft prevention in which user authentication is performed by providing a user terminal unit with an authentication key C, issued upon receiving a request for user authentication, and generating an authentication-related value corresponding to the authentication key C using a one-time random key, whereby even if the authentication key C is leaked or stolen, the fraudulent use of the authentication key C is prevented and user authentication is safely performed. 
         [0014]    In order to accomplish the above object, a system for user authentication and identity theft prevention using a one-time random key according to the present invention includes: a user terminal unit for receiving a user authentication message, which includes an authentication key (C), in response to a request for user authentication in order to use a service that requires user authentication through an arbitrary service server, creating an authentication-related value (eC) by performing an Exclusive-OR (XOR) operation on the authentication key (C) and a security key (R), which is randomly created as a one-time random key, and sending the authentication-related value (eC); and a user authentication server unit for creating the unique authentication key (C) in response to the request for user authentication, sending the user authentication message, which includes the authentication key (C), to the user terminal unit, receiving the authentication-related value (eC) as a reply thereto from the user terminal unit, creating a verification key (C′) corresponding to the authentication-related value (eC) using the security key (R), and performing user authentication by verifying the authentication-related value (eC) using the created verification key (C′). 
         [0015]    The user terminal unit may include a computer terminal, which accesses the service server and requests user authentication in order to use the service; and a mobile terminal, which receives the user authentication message in response to the request for user authentication, creates the authentication-related value (eC) by performing the XOR operation on the security key (R) and the authentication key (C), and sends the authentication-related value (eC) to the user authentication server unit. 
         [0016]    The user terminal unit may include a mobile terminal, which receives the user authentication message in response to the request for user authentication, creates the authentication-related value (eC) by performing the XOR operation on the security key (R) and the authentication key (C), and displays the authentication-related value (eC) therein; and a computer terminal, which accesses the service server and requests user authentication in order to use the service, receives the authentication-related value (eC), displayed in the mobile terminal, from a user, and sends the authentication-related value (eC) to the user authentication server unit. 
         [0017]    The mobile terminal may create the security key (R) and provide the security key (R) to the user authentication server unit. 
         [0018]    The user authentication server unit may create the security key (R) and provide the security key (R) to the mobile terminal. 
         [0019]    The mobile terminal may create the authentication-related value (eC) by performing an XOR operation on the security key (R) and a result of an XOR operation performed on the authentication key (C) and one or more of identification information and a phone number of the mobile terminal; and the user authentication server unit may create the verification key (C′) by performing an XOR operation on the security key (R) and one or more of the identification information and the phone number of the mobile terminal when receiving the authentication-related value (eC). 
         [0020]    The user authentication server unit may be configured to create the authentication key (C) using two or more one-time random keys; perform an XOR operation on remaining one-time random keys excluding a random selection key, which is randomly selected from among the two or more one-time random keys, and thereby create the verification key (C′) corresponding to the random selection key. 
         [0021]    The user authentication server unit may be configured to create the authentication key (C) using two or more one-time random keys; perform an XOR operation on remaining one-time random keys excluding a random selection key, which is randomly selected from among the two or more one-time random keys, and thereby create the verification key (C′) corresponding to the random selection key. 
         [0022]    The mobile terminal may extract a random number of bits from the created authentication-related value and send the extracted bits, and the user authentication server unit may be configured to calculate the authentication-related value (eC) by performing an XOR operation on the authentication key (C) and the security key (R) after sending the user authentication message, which includes the authentication key (C), and to create the verification key (C′) by extracting the random number of bits from the authentication-related value (eC). 
         [0023]    The mobile terminal may extract a random number of bits from the created authentication-related value and send the extracted bits to the user authentication server unit, and the user authentication server unit may be configured to calculate the authentication-related value (eC) by performing an XOR operation on the authentication key (C), the security key (R), and one or more of identification information and a phone number of the mobile terminal after sending the user authentication message, which includes the authentication key (C), and to create the verification key (C′) by extracting the random number of bits from the authentication-related value (eC). 
         [0024]    The user authentication message may be one of a short message service (SMS) message, a long message service (LMS) message, and a multimedia messaging service (MMS) message, and the user authentication server unit may send the user authentication message to the mobile terminal. 
         [0025]    The user authentication message may be one of an SMS message, an LMS message, and an MMS message, and the user authentication server unit may provide the authentication key (C) to the service server or a legacy authentication system, whereby the service server or the legacy authentication system may send the user authentication message to the mobile terminal. 
         [0026]    The mobile terminal may displays the authentication-related value (eC), and the computer terminal may receive the authentication-related value (eC) from the user and send the authentication-related value (eC) to the user authentication server unit. 
         [0027]    The computer terminal may send the authentication-related value (eC) to the user authentication server unit via the service server. 
         [0028]    The user terminal unit may include a computer terminal and a mobile terminal, the user authentication message may be a QR code, which includes the authentication key (C), the user authentication server unit may send the user authentication message to the computer terminal, the computer terminal may display the user authentication message, and the mobile terminal may acquire the authentication key (C) by scanning the QR code, which is the user authentication message displayed in the computer terminal, and may create the authentication-related value (eC) using the acquired authentication key (C) and the security key (R). 
         [0029]    In order to accomplish the above object, a method for user authentication and identity theft prevention using a one-time random key according to the present invention includes: a user authentication message sending procedure in which, when a user authentication server unit receives a notification that user authentication information matches user information in a legacy authentication system from the legacy authentication system, the user authentication server unit creates a unique authentication key (C) in response to a request for user authentication and sends a user authentication message, which includes the created authentication key (C), to a user terminal unit; an authentication-related value sending procedure in which the user terminal unit receives the user authentication message, creates an authentication-related value (eC) by performing an XOR operation on a security key (R) and the authentication key (C), and sends the authentication-related value (eC) to the user authentication server unit; and a user authentication procedure in which the user authentication server unit creates a verification key (C′) by performing an XOR operation on the authentication-related value (eC) and the security key (R) and verifies the authentication-related value (eC) using the created verification key (C′). 
         [0030]    The user authentication message sending procedure may include creating the authentication key (C) using a single random key in response to the request for user authentication; creating the user authentication message, which includes the created authentication key (C); and sending the user authentication message to the user terminal unit. 
         [0031]    The user authentication message sending procedure may include creating the authentication key (C) using two or more one-time random keys in response to the request for user authentication; creating the user authentication message, which includes the created authentication key (C); and sending the user authentication message to the user terminal unit. Also, the user authentication procedure may include performing an XOR operation on remaining one-time random keys excluding a random selection key, which is randomly selected from among the two or more one-time random keys, and thereby creating the verification key (C′) corresponding to the random selection key; and performing authentication by determining whether the verification key (C′) is identical to the created authentication key (C). 
         [0032]    The authentication-related value sending procedure may include acquiring the authentication key (C) from the user authentication message; acquiring the security key (R); and creating the authentication-related value using the authentication key (C) and the security key (R). 
         [0033]    In the creating the authentication-related value, a mobile terminal of the user terminal unit may create the authentication-related value (eC) by additionally applying one or more of unique identification information and a phone number of the mobile terminal to the XOR operation. 
         [0034]    In the creating the authentication-related value, the mobile terminal of the user terminal unit may extract a random number of bits from the created authentication-related value (eC) and send the extracted bits, and in the user authentication procedure, the user authentication server unit may perform user authentication by determining whether the extracted bits from the authentication-related value are identical to the random number of bits extracted from the verification key (C′). 
         [0035]    The extracted number of bits and the extracted bits may be randomly selected. 
         [0036]    In the user authentication message sending procedure, the user authentication server unit may send the user authentication message in a form of a mobile message to a mobile terminal of the user terminal unit, and in the authentication-related value sending procedure, the mobile terminal may create the authentication-related value (eC) and send the authentication-related value (eC) to the user authentication server unit. 
         [0037]    In the user authentication message sending procedure, the user authentication server unit may send the user authentication message in a form of a mobile message to a mobile terminal of the user terminal unit, and the authentication-related value sending procedure may further include creating, by the mobile terminal, the authentication-related value (eC) using the authentication key (C) of the user authentication message and the security key (R), and displaying, by the mobile terminal, the authentication-related value (eC); and receiving, by a computer terminal of the user terminal unit, the authentication-related value, displayed in the mobile terminal, from a user and sending, by the computer terminal, the authentication-related value to the user authentication server unit. 
         [0038]    In the user authentication message sending procedure, the user authentication server unit may send the user authentication message in a form of a QR code to a computer terminal of the user terminal unit, and the authentication-related value sending procedure may further include displaying, by the computer terminal, the user authentication message in the form of the QR code; and creating, by a mobile terminal, the authentication-related value (eC) by scanning the QR code displayed in the computer terminal and sending, by the mobile terminal, the created authentication-related value (eC) to the user authentication server unit. 
         [0039]    The security key (R) may be created by the mobile terminal in the authentication-related value sending procedure, and may then be provided to the user authentication server unit. 
         [0040]    The security key (R) may be created by the user authentication server unit after the authentication key (C) is created, and may then be provided to the mobile terminal. 
         [0041]    The present invention may be applied to an existing user authentication system, but user authentication is performed using a one-time security key, which is randomly created without inputting any information, rather than using sensitive personal information or credit information of a user, such as a social security number or the like, thus having an effect in that the personal information and credit information of the user is prevented from being leaked or illegally used by a third party. 
         [0042]    Also, the present invention performs user authentication in such a way that a user authentication server provides an authentication key C to a user terminal unit and an authentication-related value, which is the result of an XOR operation on the authentication key C and a randomly created one-time security key R, is sent to the user authentication server. Accordingly, even if an authentication message that includes the authentication key C is leaked or intercepted, a third party may not illegally use the authentication key C, a mobile phone number, or the like. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0043]      FIG. 1  is a view illustrating the configuration of a system for user authentication and identity theft prevention using a one-time random key according to the present invention; 
           [0044]      FIG. 2  is a view illustrating the configuration of a mobile terminal in a system for user authentication and identity theft prevention using a one-time random key according to the present invention; 
           [0045]      FIG. 3  is a view illustrating the configuration of a user authentication server in a system for user authentication and identity theft prevention using a one-time random key according to the present invention; 
           [0046]      FIG. 4  is a flowchart illustrating a method for user authentication and identity theft prevention using a mobile message and a one-time random key according to a first embodiment of the present invention; 
           [0047]      FIG. 5  is a flowchart illustrating a method for user authentication and identity theft prevention using a mobile message and a one-time random key according to a second embodiment of the present invention; 
           [0048]      FIG. 6  is a flowchart illustrating a method for user authentication and identity theft prevention using a QR code and a one-time random key according to a third embodiment of the present invention; and 
           [0049]      FIG. 7  is a flowchart illustrating a method for user authentication and identity theft prevention using a QR code and a one-time random key according to a fourth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0050]    Hereinafter, the configuration and operation of a system for user authentication and identity theft prevention using a one-time random key according the present invention and a method for user authentication and identity theft prevention in the system will be described with reference to the accompanying drawings. 
         [0051]      FIG. 1  is a view illustrating the configuration of a system for user authentication and identity theft prevention using a one-time random key according to the present invention. 
         [0052]    Referring to  FIG. 1 , a system for user authentication and identity theft prevention according to the present invention includes a user terminal unit  100 , a service server  200 , a user authentication server unit  300  and a legacy authentication system  400 . 
         [0053]    The user terminal unit  100 , the service server  200 , the user authentication server unit  300 , and the legacy authentication system  400  perform data communication by being connected through a wired/wireless data communication network  150 . 
         [0054]    The wired/wireless data communication network  150  is a network that includes at least one of a mobile communication network over which data communication is possible, such as a second-generation (2G) network, a third-generation (3G) network, a fourth-generation (4G) Long-Term Evolution (LTE) network, or the like, and the Internet network, in which Wi-Fi, a Wide Area Network (WAN), Local Area Networks (LANs), and the like are combined. 
         [0055]    The user terminal unit  100  includes a computer terminal  110  and a mobile terminal  120 . 
         [0056]    The computer terminal  110  may be a Personal Computer (PC), a laptop, or a smart device such as a smart phone or a smart pad. If the computer terminal  110  is a smart device such as a smart phone or a smart pad, the computer terminal  110  may be used as a mobile terminal  120 . In other words, if a terminal carried by a user is a smart device, the user may use the single terminal not only as a computer terminal but also as a mobile terminal. 
         [0057]    The computer terminal  110  may be provided with various services from any service server  200  by accessing the service server  200  through the wired/wireless data communication network  150 , and may request user authentication with the user&#39;s approval when it executes a service that requires user authentication while receiving the service. 
         [0058]    The computer terminal  110  may be configured to receive a user authentication message, which includes an authentication key C, from the user authentication server unit  300  and display it according to an embodiment of the present invention, or may be configured to receive an authentication-related value eC from a user and provide it to the user authentication server unit  300  via the service server  200  or directly send the authentication-related value eC to the user authentication server unit  300 . 
         [0059]    The mobile terminal  120  is a terminal that has its unique identification information (hereinafter, referred to as “mobile terminal identification information”) and a phone number, and may be a communication terminal such as a mobile phone, a smart phone, a smart pad, or the like, which may access at least one of 2G, 3G, and 4G mobile communication networks according to an embodiment. 
         [0060]    According to a first embodiment and a third embodiment, the mobile terminal  120  receives a user authentication message, which includes an authentication key C, from the user authentication server unit  300 , extracts the authentication key C from the received user authentication message, randomly creates a one-time random key R (hereinafter, referred to as “security key R”), and creates an authentication-related value eC by applying the extracted authentication key C and created security key R to the following Equation 1. 
         [0000]      eC=C⊕R  Equation 1
 
         [0061]    where C denotes an authentication key and R denotes a security key. 
         [0062]    Also, according to a second embodiment, the mobile terminal  120  receives a user authentication message, which includes an authentication key C, from the user authentication server unit  300 , extracts the authentication key C from the received user authentication message, receives a randomly created security key from the user authentication server unit  300 , and creates an authentication-related value eC by applying the extracted authentication key and the received random key R to Equation 1. 
         [0063]    Also, according to a third embodiment, the mobile terminal  120  receives the authentication key C of the user authentication message displayed in the computer terminal  110 , creates a security key R, which is a one-time random key, and creates an authentication-related value eC by applying the authentication key C and the created security key R to Equation 1. 
         [0064]    Also, according to a fourth embodiment, the mobile terminal  120  receives the authentication key C of the user authentication message displayed in the computer terminal  110 , receives a randomly created security key from the user authentication server unit  300 , and creates an authentication-related value eC by applying the authentication key and the received random key R to Equation 1. 
         [0065]    According to an embodiment, the created authentication-related value eC may be directly sent from the mobile terminal  120  to the user authentication server unit  300 , or may be input to the computer terminal  110  by a user and may then be sent to the user authentication server unit  300 , either directly or via the service server  200 . 
         [0066]    Also, when the mobile terminal  120  creates the security key R as in the first and third embodiments, the mobile terminal  120  must send the created security key R to the user authentication server unit  300 . 
         [0067]    Also, the mobile terminal  120  may create the authentication-related value eC by selectively applying one or more of its mobile terminal identification information and phone number, as shown in the following Equation 2. 
         [0000]      eC=C (⊕MID) (⊕TNO)⊕R  Equation 2
 
         [0068]    where MID is an acronym of Mobile IDentification and denotes mobile terminal identification information such as an Electronic Serial Number (ESN) and an International Mobile Equipment Identity (IMEI), and TNO denotes the phone number of the mobile terminal  120 . Also, ( ) represents that the information therein may be selectively applied. 
         [0069]    Also, the mobile terminal  120  extracts a random number of bits from the created authentication-related value eC based on a predetermined method of selecting bits (S[]), as in the following Equation 3, and may send the extracted bits as a final authentication-related value. 
         [0000]      eC=S[C (⊕MID) (⊕TNO)⊕R, n]  Equation 3
 
         [0070]    where n denotes the number of bits to be selected, and S is an abbreviation of Select and denotes that n bits are selected according to the predetermined method, whereby the authentication-related value eC may be created. 
         [0071]    Here, when n bits are selected, bits in random positions may be extracted using a one-time random key, which the mobile terminal  120  and the user authentication server unit  300  already know. 
         [0072]    The service server  200  provides various services, including services that require user authentication, to the computer terminal  110  of the user terminal unit  100 , which accesses the service server  200  via the wired/wireless data communication network  150 , provides the computer terminal  110  with a means for requesting user authentication when a service that requires user authentication is executed, requests the user authentication server unit  300  to perform user authentication in response to the request for user authentication from the computer terminal  110 , and provides the corresponding service to the computer terminal  110  when user authentication, performed in response to the request for the user authentication, succeeds. 
         [0073]    The legacy authentication system  400  is an existing authentication system for performing user authentication, and may be a mobile communication system, a credit assessment system, or a public certification system. Because the process of requesting authentication through the legacy authentication system  400  is known technology, a detailed description thereabout will be omitted. 
         [0074]    The user authentication server unit  300  sends information input by a user to the legacy authentication system  400  in response to a request for user authentication from the service server  200 , creates an authentication key C when it receives a notification that the information input by the user, provided for user authentication, matches user information in the legacy authentication system, sends a user authentication message, including the created authentication key C, to the user terminal unit  100 , and provides a security key R to the mobile terminal  120  of the user terminal unit  100  according to the second and fourth embodiments of the present invention. 
         [0075]    Here, the authentication key C may be a single one-time random key K, which is randomly created according to an embodiment of the present invention, or may be created using two or more one-time random keys K and R 1 , as shown in the following Equation 4. 
         [0000]      C=K⊕R 1   Equation 4
 
         [0076]    where K and R 1  denote one-time random keys. 
         [0077]    Also, according to the second and fourth embodiments of the present invention, the user authentication server unit  300  creates a security key R in response to the request for user authentication and provides the created security key R to the mobile terminal  120  of the corresponding user terminal unit  100 . After providing the authentication key C, the user authentication server unit  300  monitors whether an authentication-related value eC is received from the user terminal unit  100 , creates a verification key C′ corresponding to the authentication-related value eC and the security key R, which is acquired according to an embodiment of the present invention, when it receives the authentication-related value eC, verifies the authentication-related value eC using the verification key C′, and informs the service server  200  of the success of user authentication when the verification succeeds, whereby the service server  200  may provide the corresponding service to the computer terminal  110  of the user terminal unit  100 . Conversely, when the verification fails, the user authentication server unit  300  informs the service server  200  of the failure of user authentication. Accordingly, the service server  200  does not provide the corresponding service. 
         [0078]    The user authentication server unit  300  creates the verification key C′ using the following Equation 5 when the authentication-related value eC is created using Equation 1, creates the verification key C′ using the following Equation 6 when the authentication-related value eC is created using Equation 2, creates the verification key C′ using the following Equation 7 when the authentication-related value eC is created using Equation 3, and creates the verification key C′ using the following Equation 8 when the authentication key C is created using Equation 4. 
         [0000]      C′=eC⊕R  Equation 5
 
         [0000]      C′=eC (⊕MID) (⊕TNO)⊕R  Equation 6
 
         [0000]      C′=eC′=S[C (⊕MID) (⊕TNO)⊕R, n]  Equation 7
 
         [0000]      C′=K′=eC (⊕MID) (⊕TNO)⊕R⊕R 1   Equation 8
 
         [0079]      FIG. 2  is a view illustrating the configuration of a mobile terminal in the system for user authentication and identity theft prevention using a one-time random key according to the present invention. 
         [0080]    Referring to  FIG. 2 , the mobile terminal  120  according to the present invention includes a mobile terminal control unit  10 , a storage unit  20 , an input unit  30 , a display unit  40 , a communication unit  50 , and a scan unit  60 . 
         [0081]    The storage unit  20  includes a program area for storing a control program for controlling the operation of the mobile terminal  120  according to the present invention, a temporary area for storing data generated when the control program is executed, and a data area for storing user data. 
         [0082]    The display unit  40  displays a user authentication message according to the present invention. 
         [0083]    The input unit  30  may include one or more of a key input device, which includes multiple letter keys and function keys, and a touch pad in which letters or functions may be selected through the user interface displayed on the display unit  40  by being combined with the display unit  40 . 
         [0084]    The communication unit  50  performs data communication with other devices connected to the wired/wireless data communication network  150  by being connected to the wired/wireless data communication network  150  and includes a mobile communication unit (not illustrated) for performing data communication using a mobile communication network and a wireless Internet communication unit (not illustrated) for performing data communication using the Internet network. 
         [0085]    The scan unit  60  includes a camera, an infrared light transmission unit and an infrared light reception unit, and is configured to scan a QR code, displayed in the computer terminal  110  or the like, and to output it to the mobile terminal control unit  10 . 
         [0086]    The mobile terminal control unit  10  controls the overall operation of the mobile terminal according to the present invention and includes a message processing unit  11  for processing a user authentication message, which is received via the communication unit  50  according to an embodiment, an authentication key acquisition unit  12  for acquiring the scanned QR code from the message processing unit  11  or the scan unit  60  and acquiring an authentication key C, included in the user authentication message, through the input unit  30 , and an authentication-related value creation unit  13  for creating an authentication-related value using the acquired authentication key C and the security key R, which is created by itself or received from the user authentication server unit  300  according to an embodiment. 
         [0087]    The authentication-related value creation unit  13  creates the authentication-related value eC using one of Equations 1 to 3 according to an embodiment. 
         [0088]      FIG. 3  is a view illustrating the configuration of a user authentication server unit in the system for user authentication and identity theft prevention using a one-time random key according to the present invention. 
         [0089]    Referring to  FIG. 3 , the user authentication server unit  300  includes an authentication control unit  310 , a storage unit  340 , and a communication unit  350 . 
         [0090]    The storage unit  340  includes a user information DB for storing information about a user (hereinafter, referred to as “user information”) corresponding to the user terminal unit  100  and an authentication details DB for storing details associated with the authentication, processed according to the present invention. The user information may include one or more seed keys for creating a security key R for the user according to the embodiments (the second and fourth embodiments) of the present invention, a security key R acquired according to the embodiments (the first and third embodiments) of the present invention, and the mobile terminal identification information and the phone number of the mobile terminal  120  of the user. 
         [0091]    The communication unit  350  connects to the wired/wireless data communication network  150 , either through cables or in a wireless manner, and performs data communication with other devices connected to the wired/wireless data communication network  150 . 
         [0092]    The authentication control unit  310  includes a user registration unit  320  and an authentication processing unit  330  and controls the overall operation of the user authentication server unit  300  according to the present invention. 
         [0093]    Specifically, the user registration unit  320  provides the user terminal unit  100  with a means for registering a user as a member, receives user information about the corresponding user through the means for registering the user, and registers the user as a member by storing the received user information in the user information DB of the storage unit  340 . 
         [0094]    For the user registered as a member, the authentication processing unit  330  creates a user authentication message for user authentication and identity theft prevention according to the present invention and verifies an authentication key C, included in the user authentication message. 
         [0095]    The authentication processing unit  330  includes a user authentication message creation unit  331 , a verification key creation unit  332 , and a verification unit  333 . 
         [0096]    When user authentication is requested and a notification that user information matches user information in the legacy authentication system is received from the legacy authentication system, the user authentication message creation unit  331  creates an authentication key C, creates a user authentication message, which includes the authentication key C, and sends the user authentication message to the corresponding user terminal unit  100  via the communication unit  350 . According to an embodiment, the user authentication message may be sent as a push message through an application or an application message, may be sent as a mobile message, such as SMS, LMS, MMS, or the like, or may be sent as an Internet message. When the user authentication message is sent as an application message or a mobile message, it may be sent to the mobile terminal  120 . Alternatively, when the user authentication message is sent as an Internet message, it may be sent to one or more of the mobile terminal  120  and the computer terminal  110 . 
         [0097]    When an authentication-related value eC is received from the user terminal unit  100 , the verification key creation unit  332  creates a verification key C′ corresponding to the authentication-related value eC using one of Equations 5 to 8 according to an embodiment. 
         [0098]    The verification unit  333  verifies the authentication-related value eC using the verification key C′, which is created in the verification key creation unit  332 , and notifies the service server  200  of the result of the verification. Here, if Equation 8 is applied, the verification unit  333  uses a key K′ corresponding to the one-time random key K, which is not used to decode the verification key C′, as the verification key. Accordingly, when Equation 8 is used, the verification unit  333  performs authentication by determining whether the verification key C′ is the same as the one-time random key K. 
         [0099]    In the above description, the case in which the user authentication server unit  300  is configured as a single server is described. However, when the user authentication message is directly sent as an SMS/MMS/LMS message, the message processing unit  11  may be configured as a mobile message sending server (not illustrated), and when the authentication-related value is directly received from the mobile terminal  120 , it may be configured as an application server. 
         [0100]      FIG. 4  is a flowchart illustrating a method for user authentication and identity theft prevention using a mobile message and a one-time random key according to the first embodiment of the present invention. 
         [0101]    Referring to  FIG. 4 , first, the user terminal unit  100  accesses the service server  200  at step S 101 , and checks at step S 103  whether a user authentication event occurs, the event occurring when selecting a service that requires user authentication. 
         [0102]    When such a user authentication event occurs, the user terminal unit  100  receives user information, required for user authentication, from a user and sends a user authentication request signal, which includes the received user information, to the service server  200  at step S 105 . 
         [0103]    The service server  200  sends the user authentication request signal, which includes the user information input by the user, to the user authentication server unit  300  at step S 107  in response to the request for authentication, and the user authentication server unit  300  requests the legacy authentication system  400  to perform user authentication at step S 109  by sending the user authentication request signal thereto. 
         [0104]    The legacy authentication system  400  compares the user information, input by the user, with previously registered user information corresponding to the user, and thereby determines whether the two pieces of user information are the same as each other at step S 111 . 
         [0105]    When the two pieces of user information differ from each other, the legacy authentication system  400  sends the user authentication server unit  300  a signal for indicating the disagreement between the two pieces of user information at step S 113 , the signal including a user information disagreement notification message. Conversely, when the two pieces of user information are the same as each other, a signal indicating that the two pieces of user information are the same is sent to the user authentication server unit  300  at step S 115 . 
         [0106]    The user authentication server unit  300  determines at step S 117  whether the result of checking the user information, received from the legacy authentication system  400 , says that the two pieces of user information are the same, and then sends information about the result of checking the user information to the service server  200  at step S 119  or S 121 . 
         [0107]    The service server  200  determines whether the information about the result of checking user information says that the two pieces of user information are the same at step S 123 , and then notifies the user terminal unit  100  of the disagreement between the two pieces of user information at step S 125  when the two pieces of user information differ from each other. Conversely, when the two pieces of user information are the same, the service server sets a service waiting mode at step S 127  and waits to receive the result of user authentication. 
         [0108]    Meanwhile, the user authentication server unit  300 , which was notified that the two pieces of user information are the same, announces that the two pieces of user information are the same at step S 121 , and then creates an authentication key C at step S 129  using a single one-time random key K or by performing an XOR operation on two different one-time random keys K and R 1 , as in Equation 4. 
         [0109]    When the authentication key C is created, the user authentication server unit  300  provides the authentication key C to the service server  200 , whereby the service server  200  creates a user authentication message, which includes the authentication key C, and sends it to the mobile terminal  120  of the user terminal unit  100  at steps S 131  and S 133 . Here, the user authentication message may be sent as a mobile message such as an SMS, LMS, MMS, or the like. 
         [0110]    Alternatively, the user authentication server unit  300  itself may send a user authentication message, which include the created authentication key C, in the form of a mobile message to the mobile terminal  120  at step S 134 . 
         [0111]    Alternatively, the user authentication server unit  300  may provide the authentication key C to the legacy authentication system  400 , whereby the legacy authentication system  400  may create a user authentication message, which includes the authentication key C, and may then send it to the mobile terminal  120  of the corresponding user terminal unit  100  at steps S 135  and S 137 . Here as elsewhere, the user authentication message may be sent as a mobile message. The mobile terminal  120 , having received the user authentication message, may display the user authentication message, but may not display it in order to improve security. 
         [0112]    When the user authentication message is received, the mobile terminal  120  creates a security key R at step S 138 . 
         [0113]    When the security key R is created, the mobile terminal  120  creates an authentication-related value eC at step S 139  by applying the security key R and the authentication key C to any one of Equations 1 to 3. 
         [0114]    When the authentication-related value eC is calculated, the mobile terminal provides the created security key R to the user authentication server unit  300  at step S 141 . 
         [0115]    After provision of the security key R, the mobile terminal  120  may directly send the authentication-related value eC to the user authentication server unit  300  at step S 143 , or may send it to the user authentication server unit  300  through the computer terminal  110  of the user terminal unit  100  at steps S 145 , S 147 , S 149 , and S 151 , as represented as the dotted lines and the alternating long and short dash lines in  FIG. 4 . Here, the computer terminal  110  may directly send the authentication-related value eC to the user authentication server unit  300  through steps S 145  and S 151 , or may send it to the user authentication server unit  300  via the service server  200  through steps S 145 , S 147 , and S 149 . 
         [0116]    The user authentication server unit  300 , having received the security key R and the authentication-related value eC, creates a verification key C′ at step S 153  using an equation selected from among Equations 5 to 8, which corresponds to the equation that is used to create the authentication-related value among Equations 1 to 4. 
         [0117]    When the verification key C′ is created, the user authentication server unit  300  verifies the authentication-related value eC using the verification key C′ and determines whether the verification succeeds at step S 155 . 
         [0118]    When it is determined that the verification fails, the user authentication server unit  300  notifies the service server  200  of the failure of user authentication at step S 157 . Conversely, when it is determined that the verification succeeds, the user authentication server unit  300  notifies the service server  200  of the success of user authentication at step S 159 . 
         [0119]    The service server  200 , having received the result of user authentication, releases the service waiting mode, sends the result of user authentication to the computer terminal  110  of the user terminal unit  100  that executes the service, and provides the corresponding service to the computer terminal  110  at step S 161 . 
         [0120]    Also, after it provides the result of user authentication, the user authentication server unit  300  may store the processing details associated with user authentication in the storage unit  340  thereof for each user and for each service server  200  at step S 163 . 
         [0121]    Also, the user authentication server unit  300  may be configured to send the processing details associated with user authentication to the legacy authentication system  400  at step S 165 . 
         [0122]      FIG. 5  is a flowchart illustrating a method for user authentication and identity theft prevention using a mobile message and a one-time random key according to the second embodiment of the present invention. In  FIG. 5 , the same references numerals are used to designate the same processes of  FIG. 4 , and different reference numerals are used only for configurations that are changed according to the second embodiment. Accordingly, the description with reference to  FIG. 5  mainly focuses on the changed configurations. 
         [0123]    The authentication server unit  300  sends a user authentication message, which includes an authentication key C, to the mobile terminal  120  of the user terminal unit  100  at steps S 131  to S 133 , step S 134 , or steps S 135  and S 137 , creates a security key R at step S 210 , and provides the created security key R to the mobile terminal  120  at step S 211 . 
         [0124]    The mobile terminal  120 , having received the security key R, calculates an authentication-related value eC at step S 213  by applying the authentication key C, received from the user authentication server unit  300 , and the security key R to one of Equations 1 to 3 according to an embodiment. 
         [0125]    When the authentication-related value eC is calculated, the mobile terminal  120  directly sends the calculated authentication-related value eC to the user authentication server unit  300  at step S 215 . 
         [0126]    Alternatively, when the mobile terminal  120  displays the calculated authentication-related value eC, a user inputs the displayed authentication-related value eC to the computer terminal  110  at step S 217 , whereby the computer terminal  110  may send the input authentication-related value eC to the user authentication server unit  300 , either directly at step S 223  or via the service server  200  at steps S 219  and S 221 . 
         [0127]    The user authentication server unit  300 , having received the authentication-related value eC, calculates a verification key C′ at step S 225  by applying the received authentication-related value eC and the created security key R to a corresponding equation selected from among Equations 5 to 8. 
         [0128]    When the verification key C′ is calculated, the user authentication server unit  300  and the service server  200  perform processes based on the result of user authentication through the same steps in  FIG. 4 . 
         [0129]      FIG. 6  is a flowchart illustrating a method for user authentication and identity theft prevention using a QR code and a one-time random key according to the third embodiment of the present invention. It should be noted that, in the description below with reference to  FIG. 6 , the description about steps that are the same as those in  FIGS. 4 and 5  may be omitted or described briefly. 
         [0130]    In  FIG. 6 , when an authentication key C is created, the user authentication server unit  300  creates a user authentication message, which includes the created authentication key C, at step S 129 , and then creates a QR code including the created user authentication message at step S 311 . 
         [0131]    When the user authentication message is converted into the QR code, the user authentication server unit  300  sends the user authentication message, converted into the QR code, to one or more of the computer terminal  110  and the mobile terminal  120  of the user terminal unit  100  at step S 313 . 
         [0132]    The computer terminal  110  and the mobile terminal  120 , having received the user authentication message in the form of a QR code, display the user authentication message in the form of the QR code at step S 315 . 
         [0133]    Here, when the user authentication message in the form of a QR code is displayed in the computer terminal  110 , the mobile terminal  120  receives the code number of the QR code through the input unit  30  thereof or acquires the QR code by scanning the QR code through the scan unit  60  thereof, and then extracts the authentication key C at step S 317 . 
         [0134]    When the authentication key C is acquired, the mobile terminal  120  creates a security key R at step S 318  and creates an authentication-related value eC at step S 319  by applying the authentication key C and the created security key R to one of Equations 1 to 3. 
         [0135]    When the authentication-related value eC is created, the mobile terminal  120  provides the created security key R to the user authentication server unit  300  at step S 321 . 
         [0136]    After the security key R is sent, the mobile terminal  120  or the computer terminal  110  sends the authentication-related value eC to the user authentication server unit  300  at step S 323 , step S 331 , or steps S 325  to S 329 . 
         [0137]    Depending on the circumstances, the security key R and the authentication-related value eC may be sent together in the form of a single message. 
         [0138]    The user authentication server unit  300 , having received the security key R and the authentication-related value eC, calculates a verification key C′ at step S 333  using a corresponding equation selected from among Equations 5 to 8 and performs verification at step S 155  using the calculated verification key C′. Because the processes after the verification that are the same as those in  FIGS. 4 and 5  have been described with reference to  FIG. 4 , a description thereabout will be omitted. 
         [0139]      FIG. 7  is a flowchart illustrating a method for user authentication and identity theft prevention using a QR code and a one-time random key according to the fourth embodiment of the present invention. 
         [0140]    Referring to  FIG. 7 , when the user authentication server unit  300  sends a user authentication message in the form of a QR code, which includes an authentication key, to one or more of the computer terminal  110  and the mobile terminal  120  of the user terminal unit  100  at step S 313 , as shown in  FIG. 6 , the computer terminal  110  and/or the mobile terminal  120 , having received the QR code, may display the QR code on the screen thereof at step S 315 . 
         [0141]    After it sends the QR code, the user authentication server unit  300  creates a security key R at step S 410 , and then sends it to the mobile terminal  120  of the user terminal unit  100  at step S 411 . 
         [0142]    When the QR code is displayed in the computer terminal  110 , the mobile terminal  120  receives the code number of the QR code through the input unit  30  thereof or acquires the QR code by scanning the QR code through the scan unit  60  thereof, and then extracts the authentication key C at step S 413 . 
         [0143]    When the authentication key C is acquired, the mobile terminal  120  creates an authentication-related value eC at step S 415  by applying the security key R, received from the user authentication server unit  300 , and the authentication key C to one of Equations 1 to 3. 
         [0144]    When the authentication-related value eC is created, the mobile terminal  120  or the computer terminal  110  sends the authentication-related value eC to the user authentication server unit  300  at step S 417 , steps S 419  to S 425 , or steps S 419  and S 427 . 
         [0145]    The user authentication server unit  300 , having received the authentication-related value eC, calculates a verification key C′ at step S 429  using a corresponding equation, selected from among Equations 5 to 8, and performs verification using the calculated verification key C′ at step S 155 . 
         [0146]    Meanwhile, the present invention is not limited to the above-described preferred embodiments, and those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. It should be understood that as long as the implementation of improvements, modifications, additions and substitutions fall within the scope of the accompanying claims, the spirit thereof belongs to the scope of the present invention. 
       DESCRIPTION OF THE REFERENCE NUMERALS IN THE DRAWINGS 
       [0147]      
         [0000]    
       
         
               
               
             
           
               
                   
               
             
             
               
                 10: 
                 mobile terminal control unit 
               
               
                 11: 
                 message processing unit 
               
               
                 12: 
                 authentication key acquisition unit 
               
               
                 13: 
                 authentication-related value creation unit 
               
               
                 20: 
                 storage unit 
               
               
                 30: 
                 input unit 
               
               
                 40: 
                 display unit 
               
               
                 50:  
                 communication unit 
               
               
                 60: 
                 scan unit 
               
               
                 100: 
                 user terminal unit 
               
               
                 110: 
                 computer terminal 
               
               
                 120:  
                 mobile terminal 
               
               
                 200: 
                 service server 
               
               
                 300: 
                 user authentication server unit 
               
               
                 310: 
                 authentication control unit 
               
               
                 320: 
                 user registration unit 
               
               
                 330: 
                 authentication processing unit 
               
               
                 331: 
                 user authentication message creation unit 
               
               
                 332: 
                 verification key creation unit 
               
               
                 333: 
                 verification unit 
               
               
                 340: 
                 storage unit 
               
               
                 350: 
                 communication unit