JP6644323B1 - Tamper prevention system for electronic authentication - Google Patents

Abstract

The present invention provides a more secure cryptographic communication environment in a falsification prevention system that disperses a secret key into a plurality of dispersible values that can be restored. A system includes: a user terminal that accesses electronic information or a control target terminal to which access is restricted; an information provider that can provide electronic information to the user terminal and that can be electrically separated. , A preliminary information provider. The user terminal, the information provider, and each of the preliminary information providers store different variance values necessary for restoring electronic information or a secret key required for electronic authentication when accessing the control target terminal. The secret key is restored at the user terminal by combining the shared value stored by the user terminal with the shared value provided by the information provider and / or the preliminary information provider. If the user terminal is provided with the shared value from the spare information provider when restoring the secret key, the user terminal will not accept the provision of the shared value from the information provider substituted by the spare information provider after the next restoration. Set. [Selection diagram] Fig. 1

Description

  The present invention relates to a tamper prevention system in electronic authentication, and particularly to a confidential information required for electronic authentication when accessing electronic information to which access is restricted or a control target terminal to be controlled for which access is restricted. Security is achieved by distributing multiple variances used for key recovery to multiple information providers, including spares, and limiting the use of specific variances with the use of spare variances. The present invention relates to a falsification prevention system in electronic authentication that can increase the security.

  The performance and processing capability of smartphones and tablet terminals have been improved, and opportunities for processing highly confidential and important information such as Internet banking and virtual currency transactions via the Internet have been increasing. Along with this, important information is increasingly stored in such user terminal devices that emphasize portability. Usually, passwords and the like set by the user are used for such important information. However, it can be said that there is no risk that important information leaks due to loss of the user terminal device, hacking by a third party, unauthorized access due to password theft, and the like. Absent. The information whose access should be restricted is not limited to the user terminal device.

Recently, with the spread of IoT technology, devices and information connected to the Internet are increasing more and more, and the use value of the Internet is further increasing. Under these circumstances, communications relating to property and security, such as exchange of various important electronic information, access to important devices, and remote control through the Internet, are widely used.
Theft of personal information stored in a server or personal computer connected to the Internet, falsification of electronic data of important documents such as contracts by a third party, and unauthorized access to copyrighted works protected by copyright. Unauthorized copying or falsification of the copyrighted work itself, etc., can cause enormous economic damage to the parties and authors.

  Recently, automobiles are also equipped with control computers, and technologies for acquiring various information by communication are being developed one after another. Such automobiles have been hijacked by the control of the control computer by attacks from the Internet. If this happens, there is a risk of a fatal accident. Such safety-related risks are not limited to automobiles. For example, even in large-scale plants equipped with many IoT devices such as sensors, IoT devices that are tampered to output abnormal data or control IoT devices are controlled. Being hijacked can lead to life-threatening accidents.

While such important communications are increasing, attempts by malicious third parties to steal personal passwords, invade the system, take over, etc. occur on a daily basis on the Internet, and there is no end to this.
Therefore, many encryption communication technologies for preventing leakage, falsification, spoofing, and the like and ensuring communication security have been developed and put into practical use.

  An asymmetric encryption key system using a public key and a secret key is one of the encryption techniques generally and widely used at present. In the case of a common key method in which the sender and the receiver share a key used for encryption and decryption with each other, the information encrypted with the common key is transmitted on the transmitting side, and the information is decrypted with the common key on the receiving side. In such a case, the encrypted communication is performed, but it is necessary to send the common key to the communication partner at a stage before the encrypted communication is established. At this point, if the communication is intercepted, the common key is stolen.

  On the other hand, in the asymmetric encryption key method, information encrypted with the public key can be decrypted only with the private key, and conversely, information encrypted with the private key can be decrypted only with the public key. The sender or receiver that generates the key pair having such a relationship transmits the public key to the communication partner but does not transmit the private key but holds the key itself. If one of the communicating parties having the other party's public key encrypts the information with the other party's public key and transmits the information, only the other communicating party holding the secret key can decrypt the information. Since the information cannot be decrypted, information leakage can be prevented.

The asymmetric encryption key method is used for electronic authentication when accessing a server or the like in order to prevent spoofing or takeover, in addition to the above-described information leakage prevention. For example, when a user accesses a server that provides electronic information whose access is restricted, information necessary for authentication is encrypted with a secret key and transmitted to the server, and after decrypting with a public key on the server side, The decrypted information is collated with information necessary for authentication of a user registered in advance, and if they match, the user performs electronic authentication as a correct user holding a secret key corresponding to the public key.
However, in either case, if the secret key is stolen by a third party, leakage of information and unauthorized access to the server cannot be prevented. Therefore, prevention of the secret key theft is an important issue.

  Patent Document 1 discloses a method executed by a computer, in which n pieces of secret information restorable values are generated based on secret information used for processing of exchanged information, and the secret information is generated by the generated n Can be restored using at least k secret information restorable values of the shares, and n ≧ k ≧ 2, and the generated n secret information restorable values are replaced by n corresponding physical There is disclosed a method of deleting secret information stored in a dynamic storage device and generated. Here, the secret information is a secret key, and according to the invention of Patent Document 1, the secret information restorable value capable of restoring the secret key is stored in n physical storage devices. Since the secret key cannot be generated even if it is stolen, the security of the secret key is improved.

However, for example, when k = 2 and the secret key can be restored with two secret information restorable values, if one is stolen, one of the remaining secret information restorable values is obtained. By doing so, the secret key can be restored, and the risk of information leakage and spoofing increases.
Therefore, the risk of the secret key being stolen is reduced by distributing the secret key itself to a plurality of dispersible values that can be restored by a combination. It is desirable to provide a more secure system that prevents an increase in the risk of information leakage and spoofing.

JP 2019-05480 A

  SUMMARY OF THE INVENTION The present invention has been made in view of the problems in the above-described conventional tampering prevention system in electronic authentication, and an object of the present invention is to control access to electronic information to which access is restricted or control to which access is restricted. The multiple shared values used for the recovery of the secret key required for electronic authentication when accessing the control target terminal subject to the above are distributed and stored in multiple information providers including the spare, and the spare It is an object of the present invention to provide a falsification prevention system in electronic authentication that can increase security by restricting use of a specific dispersion value with use of a dispersion value.

  In order to achieve the above object, a falsification prevention system in electronic authentication according to the present invention, comprising: a user terminal that accesses electronic information to which access is restricted or a control target terminal to be controlled to be restricted; At least one of an information terminal capable of providing electronic information and being electrically separable, and / or an information medium providing information that can be captured by a user terminal, captured as an image, and extracted by image processing. A falsification prevention system in electronic authentication having one information provider and at least one preliminary information provider serving as a backup for the information provider, wherein the electronic information is the user terminal or the user terminal via a network. The user terminal, the information provider, and the Each of the information providers holds different shared values used for restoring a secret key necessary for electronic authentication at the time of accessing the electronic information or the control target terminal, and the secret key is the secret key, The user terminal is restored at the user terminal by combining the shared value stored with the shared value provided by the information provider and / or the preliminary information provider, and the user terminal is configured to restore the secret key when the private key is restored. When the share value is provided from the preliminary information provider, a reception prohibited state is set in which the provision of the share value from the information provider substituted by the preliminary information provider is not accepted after the next recovery of the secret key. It is characterized by the following.

  When the user terminal accesses the electronic information stored in the information providing server, or when accessing the control target terminal, the information providing server or the control target terminal is encrypted by the secret key from the user terminal. Received authentication information, decrypts the authentication information with a public key stored in the information providing server or the control target terminal, and stores user specific authentication information stored in the information providing server or the control target terminal in advance. When it matches, it is preferable to perform electronic authentication of the user terminal.

  When the user terminal accesses the control target terminal, the control target terminal, if the decrypted authentication information matches with the user specific authentication information stored in the control target terminal in advance, the It is preferable that electronic control of the user terminal is performed after a specific restriction is imposed on control of the control target terminal based on metadata of user-specific authentication information stored in the control target terminal.

  Each of the user terminal, the information provider, and the spare information provider holds a unique identification ID, and the user terminal provides the information provider or the spare that provides a shared value when restoring the secret key. It is preferable to acquire the identification ID of the information provider and determine whether or not the provision of the variance value is the preliminary information provider.

  It is preferable that the user terminal is set to be able to restart the reception of the provision of the variance value from the information provider when receiving an instruction input for canceling the reception prohibition state from the user.

  The authentication information includes an identification ID of the user terminal, the information provider and / or the preliminary information provider that provides a shared value used when the secret key is restored, and the information providing server or the control target terminal includes: In the case where the authentication information includes a specific identification ID, it is preferable not to perform electronic authentication of a source of the authentication information.

  The control target terminal confirms the identification ID of the information provider and / or the preliminary information provider included in the received authentication information, and the information provider and / or the preliminary information having the confirmed identification ID It is preferable that the electronic identification of the user terminal is not performed when the identification ID included in the received authentication information does not match the identification ID directly received from the provider when the identification ID is input.

  Based on Shamir's threshold theory, n different variances (n is a natural number) are generated based on the Shamir's threshold theory, and at least k (k is a natural number) of the n variances are calculated. The secret key can be recovered using the following equation: n and k satisfy a relational expression of n> k ≧ 2, and at least one of the n shared values used for the recovery of the secret key is first used. Preferably, the k variance values are stored one by one in the user terminal and the information provider, and the remaining variance values are stored one by one in the spare information provider.

  The information medium is a printed matter on which information created by a two-dimensional barcode or a digital watermark technique is printed, or an electronic apparatus including a display device capable of providing information created by a two-dimensional barcode or a digital watermark technique as an image. thing

  The electronic information to which the access is restricted is the user terminal or the electronic information with high importance in the information providing server, and the electronic information with high importance is a contract, a copyrighted work, At least one of personal information is included, and the control target terminal is at least one of a car, a drone, a smart maker, an IoT device, a communication router, an IoT device control terminal, a robot, and an artificial satellite. It is preferable to include one.

  According to the tampering prevention system in the electronic authentication according to the present invention, the electronic information whose access is restricted, the secret key required for electronic authentication when accessing the control target terminal which is the target of the control whose access is restricted, The required number is combined to distribute the secret key into a plurality of shared values from which the secret key can be restored, and each shared value is assigned to a separate information provider (user terminal, information terminal, spare information terminal, or two-dimensional barcode). Etc.), the risk of secret key theft is reduced, and even if an information provider storing one of the shared values is stolen, the provision of the stolen information when the spare shared value is used Since the use of the variance of the body is prohibited, it is possible to provide a secure cryptographic communication environment without increasing the risk of information leakage, spoofing, or tampering with intrusion into the system due to spoofing. It made.

  Further, according to the falsification prevention system in the electronic authentication according to the present invention, since the identification ID of the information provider can be embedded so that it can be separated into specific digits of the dispersion value, even if the information provider is stolen. Since the dispersion value itself cannot be extracted unless the identification ID of the information provider is separated, a highly secure cryptographic communication environment can be provided.

  Further, according to the falsification prevention system in the electronic authentication according to the present invention, at the time of electronic authentication by the control target terminal, the control of the control target terminal is performed based on the metadata of the user-specific authentication information stored in the control target terminal in advance. Because user terminals can be authenticated electronically with specific restrictions, the range of use of controlled terminals can be limited by the age of the user, and the functions that can be used by controlled terminals can be limited according to the user's qualifications. Or you can.

  According to the tampering prevention system in the electronic authentication according to the present invention, the control target terminal checks the identification ID of the information provider and / or the preliminary information provider from the authentication information transmitted from the user terminal in response to the access request. Then, it is required to input the identification ID directly from the information provider and / or the preliminary information provider having the confirmed identification ID, and the identification ID included in the received authentication information matches the identification ID directly input. Otherwise, the electronic authentication of the user terminal will not be performed, and the electronic authentication will not be performed unless the information provider and / or the preliminary information provider are actually possessed at hand. Therefore, security to prevent impersonation of a third party It is possible to provide a cryptographic communication environment with a high level of security.

1 is a block diagram schematically illustrating a configuration of a falsification prevention system in electronic authentication according to an embodiment of the present invention. FIG. 4 is a diagram illustrating distribution of a distribution value for restoring a secret key of the falsification prevention system in electronic authentication according to the embodiment of the present invention. It is a block diagram showing roughly composition of a falsification prevention system in electronic authentication by other embodiments of the present invention. 5 is a flowchart illustrating a method of accessing electronic information of a user terminal according to an embodiment of the present invention. 9 is a flowchart illustrating a method for accessing electronic information of an information providing server according to another embodiment of the present invention. 9 is a flowchart illustrating a method of accessing a control target terminal according to another embodiment of the present invention.

Next, a specific example of an embodiment for implementing a falsification prevention system in electronic authentication according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram schematically showing a configuration of a falsification prevention system in electronic authentication according to an embodiment of the present invention.
Referring to FIG. 1, a falsification prevention system 1 in electronic authentication according to an embodiment of the present invention includes a user terminal 10, an information provider 20, and a preliminary information provider 30.

  The tampering prevention system in the electronic authentication according to the present invention is a system for mutual protection used for restoring a secret key necessary for accessing electronic information whose access is restricted or a controlled terminal to be controlled whose access is restricted. By distributing different shared values to a plurality of information providers including user terminals and spares in advance and retaining the secret keys with a single device unless a predetermined number of shared values are available, it is not possible for a single device to recover the secret key. Is a system that prevents unauthorized access and tampering by a third party, and furthermore, if there is a risk that one of the variances may be stolen due to loss, etc., using a spare variance may result in the risk of plagiarism This is a more secure tamper-proof system because the use of the variance value is no longer accepted.

  Here, the information provider is an information terminal that can provide electronic information to the user terminal and that can be electrically separated, or information that provides information that can be captured by the user terminal as an image and extracted by image processing. It is a general term for a medium, and a spare information provider that is a spare for an information provider is not different in content from an information provider. The information terminal is, for example, a memory card, a USB memory, an IC card, a smartphone, a tablet terminal, a personal computer, or the like. The information medium is, for example, a printed matter on which information created by a two-dimensional barcode or a digital watermark technique is printed, or Examples of the electronic device include a smart phone, a tablet terminal, and a personal computer that include a display device capable of providing, as an image, information created by a three-dimensional barcode or a digital watermark technique.

  The falsification prevention system in the electronic authentication according to the present invention is such that even after the use of the variance value in which the risk of plagiarism has occurred cannot be accepted, one loss of the variance value is temporary, and When the risk of being found and plagiarized is eliminated, a request for canceling the prohibition of the variance value can be input and restored, so that the system is also convenient for the user.

  The falsification prevention system 1 shown in FIG. 1 is a system corresponding to an embodiment in which electronic information whose access is restricted is stored in a user terminal 10, wherein an information provider 20 is an information terminal, and a preliminary information provider 30 is a preliminary information. This is the case of the terminal. In the falsification prevention system 1 shown in FIG. 1, the shared value stored in the user terminal 10 and used for restoring the secret key required for accessing the electronic information whose access is restricted is stored in the user terminal 10 and the information. The distribution key is distributed and stored in the provider 20 and the preliminary information provider 30, and the recovery value of the secret key requires at least the distribution value stored in the user terminal 10 and the information provider 20 and / or the preliminary information provider 30. Becomes

  FIG. 1 shows a case where each of the information provider 20 and the preliminary information provider 30 is one. However, the information provider 20 and the preliminary information provider 30 depend on the number of sharing values used for the recovery of the secret key. May be more than one each.

  The user terminal 10 includes a control unit 11, an input / output unit 12, a storage unit 13, a display unit 14, a secret key generation unit 15, a shared value information management unit 16, and a secret key authentication unit 17.

  The secret key generation unit 15 generates a secret key required to access electronic information whose access is restricted. In order to safely store the electronic information whose access is restricted, the target electronic information may be encrypted and stored. In this case, the secret key generation unit 15 generates the secret key together with the public key to be paired with the secret key. The public key is a key that can be used to encrypt electronic information. The electronic information encrypted with the public key cannot be decrypted by the public key itself, but can be decrypted only by the private key. For this reason, if the secret key is stored in the user terminal 10 in a visible state, when the user terminal 10 is stolen, the encrypted electronic information can be decrypted with the secret key and the contents of the electronic information can be viewed by a third party. May be altered or tampered with.

  Therefore, after generating the secret key, the secret key generation unit 15 generates a plurality of different shared values that can restore the secret key. For example, in accordance with Shamir's threshold theory, if the number of shared values necessary for the recovery of the secret key is k, a k-1 order polynomial f (x) is created, and f (0) is set as a secret value. Arbitrary different points that satisfy the key value and the polynomial f (x) are set as variance values. In the k-1 degree polynomial f (x), if there are k points satisfying this, the k-1 degree polynomial f (x) is uniquely specified, and therefore, the secret key f (0) is obtained. Can be. However, the secret key f (0) cannot be obtained because all the constants of the polynomial f (x) cannot be obtained when the number of points satisfying the k-1 degree polynomial f (x) is k-1 or less.

Utilizing such a property of the polynomial, the secret key generation unit 15 generates a plurality of different variance values. At this time, in addition to the number necessary for the recovery of the secret key, the secret key generation unit 15 generates I do. That is, assuming that the number of shared values generated by the secret key generation unit 15 is n and the number necessary for restoring the secret key is k, the two natural numbers n and k satisfy the following equation (1). Is generated.
n> k ≧ 2 (1)

As described above, the secret key cannot be restored unless at least two share values are prepared, and the secret key is generated so as to include at least one spare share value. The electronic information whose access is restricted is information of high importance, and such electronic information of high importance includes at least one of a contract, a work protected by copyright, and personal information. Since these highly important electronic information is information that must be read when necessary, by generating a spare dispersion value, even if one of the dispersion values becomes unusable due to loss or damage, etc. Thus, the problem of inaccessibility can be avoided.
The shared value generated by the secret key generation unit 15 is distributed and stored in the user terminal 10, the information provider 20, and the preliminary information provider 30, and the distributed storage will be described later with reference to FIG.

  After the share value used for restoring the secret key is generated, the secret key can be restored if the necessary share values are aligned, so that it is not necessary to keep the original form. Therefore, after a shared value is generated and stored in a distributed manner, the original secret key may be deleted. In one embodiment, in order to use the secret key for electronic authentication of the user, after processing such as adding specific information to the secret key, the secret key is encrypted with the public key paired with the secret key and stored in the storage unit 13. I do. The variance value other than the variance value held by the user terminal 10 is deleted from the user terminal 10 at the stage when the variance value is distributed to the information provider 20 and the preliminary information provider 30.

  Note that a secret key and a shared value for restoring the secret key are generated by another device different from the user terminal 10, and the shared value is distributed in advance to the user terminal 10, the information provider 20, and the preliminary information provider 30. May be saved. In this case, the secret key generation unit 15 does not need to perform the above-described initial secret key generation and the generation of the shared value necessary for the secret key restoration.

  When accessing the electronic information whose access is restricted, the secret key generation unit 15 uses the shared value stored in the user terminal 10 itself and the secret key recovery acquired from the information provider 20 and / or the preliminary information provider 30 to access the electronic information. The secret key is restored by combining with the required remaining share value.

The shared value information management unit 16 determines whether the shared value for secret key recovery is distributed to which information provider 20 or the spare information provider 30 in addition to the user terminal 10, and that each shared value can be used. Information on the variance value such as whether or not is updated and managed as variance value information.
The variance value provider in which the variance value is stored (the user terminal 10, the information provider 20, and the preliminary information provider 30, hereinafter, the components holding the variance value so as to be able to provide the variance value are also collectively referred to as the variance value provider). In the tampering prevention system 1, a unique identification ID is assigned to each variance value provider.

Since the shared value provider is identified by the unique identification ID in this manner, the falsification prevention system 1 loses or steals the information provider 20 in which the shared value normally used for the secret key is stored. When the preliminary information provider 30 that stores the preliminary dispersion value is used, the original information provider 20 substituted by the preliminary information provider 30 has a risk of being misused by a third party. The variance value from the information provider 20 can be prohibited.
The unique identification ID may be generated together with the generation of the variance value, and may be stored in each variance value provider together with the variance value. Also, in one embodiment, the unique identification ID may be embedded such that it can be separated into specific digits of the variance.

  When the secret key generation unit 15 obtains the share value from the information provider 20 or the preliminary information provider 30 for the recovery of the secret key, the secret key generation unit 15 obtains the identification ID together with the share value, thereby recovering which share value. Can be identified. When the identification ID is embedded in the variance value, the variance value and the identification ID can be separated from each other to identify which identification ID the variance value is based on.

The variance value information management unit 16 stores a serial number of the generated variance value, an identification ID of the variance value provider in which the variance value of the serial number is stored, and a flag indicating whether or not each variance value can be used. It is managed and stored in the storage unit 13.
For example, the flag indicating whether or not the variance value can be used is set to “0” if the variance value can be used. "1" is recorded and distinguished. In one embodiment, the share value stored in the preliminary information provider 30 may be set to a flag “2” to be distinguished from the information provider 20 in which the share value used for the secret key on a daily basis is stored. By making such a distinction, the use of the spare variance can be easily identified. If a spare variance is used if necessary, the user terminal 10 may request a password registered in advance.

When restoring the secret key, the secret key generation unit 15 passes the identification ID obtained together with the share value to the share value information management unit 16, and the share value information management unit 16 refers to a table managed by the share value information management unit 16. Then, the latest flag for the transferred ID is returned to the secret key generation unit 15.
The secret key generation unit 15 confirms the returned flag, and does not restore the secret key if the flag “1” for which the acceptance is prohibited is input to the ID of the share value provider that has obtained the share value.

  When the secret key generation unit 15 restores the secret key, the flag corresponding to the identification ID acquired together with the share value includes the flag “2” indicating that the share value is the share value from the preliminary information provider 30 for the first time. The request is made to the distributed value information management unit 16 to change the flag for the information provider 20 that has not been used, that is, the information provider 20 that has been substituted by the preliminary information provider 30, to a value “1” indicating the prohibition of reception. As a result, the information receiving body 20 that is at risk of being lost or stolen and being misused by a third party is set to a reception prohibited state for the next and subsequent times.

  When the user tries to access the electronic information whose access is restricted, the information provider 20 in which the shared value used for the secret key is stored on a daily basis by chance is not found, and the auxiliary information provider 30 is unavoidably used. Accessing the electronic information may occur. In this case, the information provider 20 that has not been found is automatically set to a reception prohibited state for the recovery of the secret key. Therefore, even if this information provider 20 is found later, access is restricted from the next time. Can no longer be used to access electronic information. In addition, since the spare variance value decreases with this, if the same loss occurs next time, it may be impossible to access necessary electronic information.

  Therefore, when the flag corresponding to any one of the information providers 20 is changed to the value “1” indicating the prohibition of reception, the secret key generation unit 15 allows the user to input an instruction to cancel the prohibition of reception. Thus, the input screen is provided on the display unit 14 of the user terminal 10. For providing the input screen, for example, an icon may be displayed on the display unit 14 for guiding the user to a screen for performing an input for instructing cancellation of the reception prohibited state.

When the user instructs to release the reception prohibition state, the flag corresponding to the identification ID of the corresponding information provider 20 is returned from “1” indicating reception prohibition to “0” indicating use permission.
Here, the values of the flags are shown as being distinguished as "0", "1", and "2", but this is one embodiment, and it is not necessary to limit to such numerical values. As long as it is possible to identify whether each variance value is usable or not, it may be a character or another notation method.

  When the user attempts to access electronic information whose access is restricted, the secret key authentication unit 17 performs electronic authentication of the user. When the secret key generation unit 15 restores the secret key as described above, the secret key authentication unit 17 checks the flag for the identification ID of the share value providing entity that provides the share value. If the secret key is restored without using the provided information provider 20, the possibility of unauthorized use is low, and the user may be electronically authenticated by restoring the correct secret key. In addition, after processing such as adding specific information to the private key, if the encrypted private key is stored, the secret key information processed and stored is restored by the restored private key. Confirm the consistency between the decrypted and restored private key and the decrypted private key, and confirm the decrypted specific information such as identification ID information to be used for recovering the private key and the password required for recovery. Alternatively, the user may be electronically authenticated.

  The input / output unit 12 includes a data input unit for inputting information such as a shared value and an identification ID required for secret key recovery from the information provider 20 and the preliminary information provider 30. It also has a data output means for generating a shared value required for secret key recovery and storing it in the information provider 20 and the preliminary information provider 30 in a distributed manner. In addition, the apparatus includes any one of input means, such as a keyboard, a touch panel, and a mouse, for the user to input an instruction to cancel the reception prohibited state to the information provider 20 or to select an icon. If the electronic information whose access is restricted requires information exchange via a communication line, such as a virtual currency wallet, a communication means is also provided.

  The information provider 20 and the preliminary information provider 30 can be in various forms such as a memory card, a USB memory, an IC card, a smartphone, a tablet terminal, and a personal computer. An output unit is provided. The data input / output means is, for example, a terminal for inserting in the case of a memory card or a USB memory, and is a communication means for short-range wireless communication in the case of an IC card.

  The storage unit 13 stores electronic information for which access is restricted, in addition to the variance value and the identification ID of the user terminal 10 itself. The storage unit 13 also stores programs such as a dedicated application for generating and restoring a secret key in the user terminal 10 and a control program for controlling the basic operation of the user terminal 10 itself. The storage unit 13 is embodied by storage means such as a memory semiconductor or a hard disk drive.

The display unit 14 displays electronic information for which access is restricted, and displays an input screen for instructing the information provider 20 to cancel the reception prohibited state. Further, a program such as a control program is displayed as necessary. The display unit 14 is embodied by a liquid crystal panel, an organic EL panel, or the like.
The control unit 11 controls the components of the user terminal 10 to perform the functions described above. The control unit 11 is embodied by a control circuit including a semiconductor device such as a microcomputer.
The user terminal 10 is embodied by a smartphone, a tablet terminal, a personal computer, or the like.

  When the information provider 20 is an electronic device such as an information terminal, the information provider 20 includes a control unit 21, an input / output unit 22, and a storage unit 23. The information provider 20 may provide any type of electronic device that can provide the user terminal 10 with electronic information including a variance value and an identification ID and that can be electrically separated. For example, the information provider 20 is a memory card, a USB memory, an IC card, a smartphone, a tablet terminal, a personal computer, or the like. When three or more shared values to be used for restoring the secret key are required, the number of information providers 20 is plural. In this case, the plurality of information providers 20 may be the same, or different types of devices may be used. There may be.

  The input / output unit 22 outputs the variance value and the identification ID stored in the information provider 20 to the user terminal 10, and outputs the variance value and the identification value from the user terminal 10 or other devices that generate the variance value in the initial stage. Receives input of ID. The input / output of such data is performed through an input / output terminal when the information provider 20 is a memory card or a USB memory, and through a short-range wireless communication unit when the information provider 20 is an IC card. When the information provider 20 is a smartphone, a tablet terminal, a personal computer, or the like, communication with the user terminal 10 is possible via a wide area network. Since the risk of outflow of data increases, provision of the variance value to the user terminal 10 is limited to transmission and reception of data by short-range wireless communication or wired connection.

The storage unit 23 stores a shared value and an identification ID used for restoring a secret key. The storage unit 23 is embodied by storage means such as a semiconductor memory device or a hard disk drive according to the form of the information provider 20.
The control unit 21 controls the input / output unit 22 and the storage unit 23 to perform the above functions.

  The spare information provider 30 is used as a spare for the information provider 20 that stores the shared value used for restoring the secret key. When the spare information provider 30 is also an electronic device, the spare information provider 30 Similarly, the variance value and the identification ID are stored. The spare information provider 30 is the same as the information provider 20 except that the spare information provider 30 is used as a spare and is different in its position as a terminal device. As the information provider 20 has various device forms such as a memory card, a USB memory, an IC card, and the like, the device form of the preliminary information provider 30 is also various. The device form of the provider 20 may be the same or different. When there are a plurality of preliminary information providers 30, the plurality of preliminary information providers 30 may be in the same device form or may be different from each other.

  In FIG. 1, the preliminary information provider 30 is shown to include a control unit 31, an input / output unit 32, and a storage unit 33, which are respectively included in the control unit 21, the input / output unit 22, and the information provider 20. It is not substantially different from the storage unit 23.

  As described above, the information provider 20 and the preliminary information provider 30 in the falsification prevention system 1 shown in FIG. 1 are electronic devices called an information terminal and a preliminary information terminal, respectively. Reference numeral 30 may be an information medium that provides information that can be captured and captured as an image by the user terminal 10 and extracted by image processing. The information medium is, for example, a printed matter on which information created by a two-dimensional barcode or a digital watermark technology is printed, or an electronic device including a display device capable of providing information created by a two-dimensional barcode or a digital watermark technology as an image. is there.

When the information provider 20 and the preliminary information provider 30 are printed matter, the information provider 20 and the preliminary information provider 30 are control units (21, 31) as shown in the information provider 20 and the preliminary information provider 30 in FIG. , Input / output units (22, 32) and storage units (23, 33), and has information such as a variance value and an identification ID as an image printed on a medium such as paper. The information is provided to the terminal 10 as an image.
In this case, although not shown in FIG. 1, the user terminal 10 obtains an image provided by the information provider 20 and the preliminary information provider 30 by using an image acquisition unit such as a camera and image processing from the acquired image. It further includes an image processing unit for extracting necessary information.

  When the information provider 20 and the preliminary information provider 30 are electronic devices including a display device capable of providing information such as a variance value as an image, the information provider 20 and the preliminary information provider 30 are the information provider of FIG. 20, including components such as a control unit (21, 31), an input / output unit (22, 32), and a storage unit (23, 33) as shown in the preliminary information provider 30, and provides information as an image. A display device is provided. Also in this case, the user terminal 10 includes the image acquisition unit and the image processing unit, similarly to the case where the information provider 20 and the preliminary information provider 30 are printed matter.

  In the above description, the information provider 20 and the preliminary information provider 30 are both electronic devices such as an information terminal and a preliminary information terminal, both electronic devices having a display device capable of providing information as printed matter or both as images. As described above, the information provider 20 and the preliminary information provider 30 need not be of the same type, and the information provider 20 is an information terminal and the preliminary information provider 30 is different from a printed matter providing an image. A variance value provider that provides a type of variance value may be used.

  The generation of the secret key, the generation of the shared value, the decryption of the secret key by obtaining the shared value, and the like performed by the user terminal 10 are performed in advance or by a dedicated application provided to the user terminal 10 later. The dedicated application may be downloaded to the user terminal 10 from a Web site provided by a server that provides the dedicated application. The dedicated application may be common regardless of the user terminal 10 to download, or may be provided in a different form individually for each user terminal 10 to download. When provided in a different form for each user terminal 10, the variance value stored in the user terminal 10 is provided in a form embedded in a dedicated application so that it is not necessary to separately store the variance value in the storage unit 13 as a variance value. May be provided.

FIG. 2 is a diagram for explaining distribution of a shared value for restoring a secret key of the falsification prevention system in electronic authentication according to the embodiment of the present invention.
Referring to FIG. 2, first, a shared value necessary for restoring a secret key is generated. FIG. 2 shows an embodiment in which n (n is a natural number) including the spares are generated as the share values, and the secret key can be restored using k (k is a natural number) among them.

  The generation of the share required for the recovery of the secret key may be performed by the user terminal 10 or may be performed by another device different from the user terminal 10. The same number of identification IDs as the number of variance values generated with the generation of the variance value are generated. The generated variance value and identification ID are distributed and stored in a variance value provider prepared in advance. The identification ID may be prepared in advance and stored in each variance value provider that stores the variance value. When the variance value provider is a printed matter, the variance value and the identification ID are stored in the variance value provider by being printed on a medium such as paper as an image including such information. The variance value and the identification ID may be printed as individual images, or may be printed as an image including both the variance value and the identification ID.

  For convenience, the generated n variances are numbered sequentially from 1 to n. Among them, the first variance is stored in the user terminal 10, and the second to k-th variances are stored in the information provider 20 (20_20). (1),... 20_ (k-1)). The remaining k + 1 to n-th variance values are stored in the preliminary information provider 30 (30_ (1),..., 30_ (nk)).

  In the embodiment of FIG. 2, the user terminal 10 that stores the first variance value is a smartphone that stores A001 as the identification ID, and the information provider 20_ (1) that stores the second variance value includes the identification ID The information provider 20_ (k-1) that stores the k-th variance value is a USB memory that stores A00k as the identification ID, and a spare memory that stores the (k + 1) -th variance value. The information provider 30_ (1) is a memory card that stores A00k + 1 as the identification ID, and the spare information provider 30_ (nk) that stores the nth variance value is a two-dimensional memory that holds A00n as the identification ID. This is a printed matter on which a code is printed. As described above, various forms can be applied to the variance value provider that stores the variance value. A combination of other variance value providers as shown in FIG. 2 may be used, or a variance value provider of the same type may be used.

The user terminal 10 stores the first variance value stored in the user terminal 10 and the second to k-th variance values stored in the information provider 20 (20_ (1),..., 20_ (k-1)). Combine to recover private key.
The n share values are not originally distinguishable, and the secret key can be restored using any k share values. For convenience, the share values that are routinely used for the secret key restoration are defined as the first share values. To the k-th variance value, and the other variance values are classified as spare variance values. That is, the information provider 20 saves the share value that is used to restore the secret key on a daily basis, and the spare information provider 30 saves the spare share value. By properly using in this way, it is possible to recognize that a risk of theft has occurred when a different variance value is used.
The variance value information management unit 16 of the user terminal 10 manages a serial number of the variance value, an identification ID corresponding to the variance value, and a flag indicating whether or not each variance value can be used in a table in association with each other.

  In FIG. 2, the variance value provider that stores the second to kth variance values in advance is shown as the information provider 20. However, at the stage of storing the variance values, the variance value providers are not distinguished from each other. Of the share value providers used when the secret key was restored for the first time, an information provider 20 other than the user terminal 10 and a share value provider that stores the share values not used for the secret key restoration are reserved. The information provider 30 may be used, and the flag of the preliminary information provider 30 may be set to a flag “2” indicating that the information provider 30 is a backup.

FIG. 3 is a block diagram schematically showing a configuration of a falsification prevention system in electronic authentication according to another embodiment of the present invention.
Referring to FIG. 3, a falsification prevention system 2 in electronic authentication according to another embodiment of the present invention includes a user terminal 10, an information provider 20, a preliminary information provider 30, and information connected to the user terminal 10 via a network 60. The control target terminal 50 is connected to the providing server 40 or the user terminal 10 via the network 60. Network 60 is a wide area network such as the Internet.

  The tampering prevention system 2 in the electronic authentication according to another embodiment of the present invention is different from the tampering prevention system 1 in the electronic authentication shown in FIG. 1 in that the tampering prevention system 2 is connected to the user terminal 10 via the network 60. This is the point that the information providing server 40 and / or the control target terminal 50 connected to the user terminal 10 via the network 60 are provided. Another difference is that electronic information to which access is restricted is stored not in the user terminal 10 but in the information providing server 40.

A shared value for secret key recovery is generated by the user terminal 10 or another device different from the user terminal 10, and the shared value is stored in advance in the information provider 20 and the spare information provider 30 together with the identification ID. A secret key is generated in the terminal 10 by combining the share value stored by the user terminal 10 itself with another share value necessary for the secret key restoration obtained from the information provider 20 and / or the preliminary information provider 30. The facts are the same as those described in the falsification prevention system 1.
However, since the electronic information whose access is restricted is not stored in the user terminal 10, the user terminal 10 does not necessarily need to perform electronic authentication of the user, and thus the user terminal 10 does not have the secret key authentication unit 17. Is also good.

In the falsification prevention system 2, the target to which access is restricted is stored in a physically different position from the user terminal 10. Therefore, when accessing the target to which access is restricted from the user terminal 10, the electronic authentication of the user terminal 10 is performed. Is required.
Hereinafter, a case in which access is restricted to electronic information stored in the information providing server 40 will be described.

  The information providing server 40 includes a control unit 41, an input / output unit 42, a storage unit 43, a display unit 44, a secret key authentication unit 45, a user information management unit 46, and a content management unit 47.

The user information management unit 46 manages information of a user who registers electronic information whose access is restricted. A user who wishes to register electronic information to which access is restricted first accesses the registration screen of the Web site provided by the information providing server 40 using the user terminal 10, and inputs personal information such as a name, an e-mail address, and a password required for login. Register information. The user information management unit 46 issues a unique user ID for each user at the time of initial registration of the user, transmits the user ID to the user terminal 10, and sets a user-specific display screen My Page on the Web site. The next time the user accesses the My Page of the information providing server 40, the user needs to enter a user ID and a password.
The user information management unit 46 manages the registered personal information such as the user ID and the password in association with each other, and stores the personal information in the storage unit 43.

  When the user transmits electronic information to be stored in the information providing server 40 from the user terminal 10, the content management unit 47 associates the electronic information with the transmission source user ID, and stores the information in the storage unit 43 for each user. Further, when the electronic information that the user wants to save in the information providing server 40 is important electronic information that may cause a serious loss to the user due to falsification, the content management unit 47 deletes the received important electronic information. The information is stored separately for each user as information requiring special electronic authentication, separately from general electronic information.

Important electronic information is encrypted and transmitted at the user terminal 10 so that even if the important electronic information is stolen during transmission from the user terminal 10, the content cannot be read. In this case, the content management unit 47 stores the electronic information in the storage unit 43 while being encrypted. The key used for encryption is either a public key previously transmitted to the user terminal 10 or a private key generated by the user terminal 10 among a pair of a secret key and a public key generated on the information providing server 40 side. It is preferably a public key generated as a private key pair key.
The content management unit 47 separates registration screens on the user's My Page so that the user can upload and register the electronic information to be registered as general electronic information or important electronic information requiring access restriction. May be provided.

  When the user uses the user terminal 10 to access electronic information whose access is restricted, the secret key authentication unit 45 performs electronic authentication of the user. When a user registers electronic information whose access is restricted to the information providing server 40 or at the time of initial user registration, the user terminal 10 and the information providing server 40 respectively use a secret key and a public key which is a pair key of the secret key. Is generated, and the public keys are exchanged and stored. Information encrypted with a public key can only be decrypted with a private key that is paired with the information. Conversely, information encrypted with a secret key can only be decrypted with a paired public key.

Normally, when sending and receiving important electronic information, the sender encrypts important electronic information with the public key of the destination received from the destination, transmits it, and receives the encrypted electronic information at the destination. Important electronic information can be transmitted safely by decrypting with the secret key of the user.
On the other hand, in the case of electronic authentication, on the assumption that the private key that is a pair of the sender's public key is held only by the legitimate sender, the sender receives the authentication information encrypted with the sender's secret key. First, the electronic information is decrypted with the public key received in advance from the transmission source, and electronic authentication is performed when the authentication information registered in advance matches the decrypted authentication information.

Therefore, when the user registers the electronic information whose access is restricted to the information providing server 40, the user terminal 10 encrypts the information with the public key of the information providing server 40 received from the information providing server 40 in advance and stores the encrypted information in the information providing server 40. Submit and register.
However, if the information providing server 40 only registers and stores electronic information whose access is restricted, it is not necessary to decrypt the electronic information on the information providing server 40 side. The information may be stored in the information providing server 40 while being encrypted. When the user browses or revise the electronic information to which access is restricted, the user downloads the electronic information in an encrypted state, restores the secret key of the user terminal 10 by using a shared value, and restores the electronic information. Can be decrypted. The revised electronic information is again encrypted with the public key of the user terminal 10 and transmitted to the information providing server 40 to be updated.

In order to access the electronic information whose access has been restricted registered in the information providing server 40, electronic authentication is required from the next time. Therefore, when attempting to access electronic information whose access is restricted from the user terminal 10, the secret key authentication unit 45 requests the user terminal 10 to transmit authentication information. On the other hand, when the authentication information is encrypted from the user terminal 10 using the restored secret key and transmitted, the secret key authentication unit 45 decrypts the received authentication information with the public key of the user terminal 10 obtained in advance, and performs authentication. If the user information matches the authentication information included in the personal information managed by the user information management unit 46 in advance, the user is electronically authenticated. As described above, the authentication information is selected from arbitrary items included in the personal information.
If the authentication information registered in advance does not match the decrypted authentication information, the electronic authentication of the user is rejected, so that impersonation can be prevented.

  Further, when the secret key and the shared value are generated at the user terminal 10 or when the secret key is restored by the shared value at the user terminal 10, the identification of the shared value provider used for restoring the secret key from the user terminal 10 is performed. The ID is transmitted to the information providing server 40 and registered in advance, and when the authentication information is generated at the user terminal 10, the identification ID used for restoring the secret key required for encryption is used as the authentication information. May be included. Accordingly, the secret key authentication unit 45 can determine the validity of the user including the identification ID of the shared value provider used for the recovery of the secret key and perform the electronic authentication.

  As described with reference to FIG. 1, even when the acceptance prohibited state is set for a specific variance value provider or the acceptance prohibited state is subsequently released, the flag of the variance value provider is transmitted from the user terminal 10 each time. Is transmitted to the information providing server 40 and updated, so that the secret key authentication unit 45 can determine the legitimacy of the user including whether or not the secret key is restored using the shared value from the correct shared value provider. It becomes possible, and when the identification ID of the specific distributed value provider in which the reception prohibited state is set is included, the secret key authentication unit 45 does not perform the electronic authentication, so that the tampering prevention system 2 with higher security can be provided. is there.

  The input / output unit 42 includes communication means for receiving various information such as personal information, electronic information, and authentication information from the user terminal 10 via the network 60 and exchanging public keys. The information providing server 40 also has input means such as a keyboard and a mouse for inputting character information and instructions.

  The storage unit 43 stores a control program for controlling the information providing server 40, in addition to the user's personal information and electronic information transmitted from the user terminal 10, and the like. The storage unit 43 may store an area for storing electronic information whose access is restricted, separately from an area for storing general electronic information. The storage unit 43 is embodied by a storage device such as a semiconductor memory device or a hard disk drive.

The display unit 44 includes a display screen that displays a control program for controlling the information providing server 40, if necessary, in addition to the user's personal information transmitted from the user terminal 10, and the like.
The control unit 41 controls each component of the information providing server 40 to perform the above function, and is embodied by a control board including a microprocessor.

  The falsification prevention system 1 in which the electronic information whose access is restricted is stored in the user terminal 10 and the falsification prevention system 2 in which the electronic information whose access is restricted is stored in the information providing server 40 have been described. The electronic information to be stored may be stored in both the user terminal 10 and the information providing server 40. In this case, the falsification prevention system 1 and the falsification prevention system 2 may be configured such that the contents described in the falsification prevention system 2 apply. Be composed.

The target for which access is restricted is not limited to electronic information stored in the user terminal 10 or the information providing server 40. As shown in FIG. 3, the same electronic authentication can be applied to the control target terminal 50 whose access is restricted.
Here, the control target terminal 50 whose access is restricted is a device having high importance such as handling security and confidential information, such as a car, a drone, a smart maker, an IoT device, a communication router, an IoT device control terminal, and the like. It includes at least one of a robot and an artificial satellite. If the control target terminal 50 to which access is restricted cannot be accessed in an emergency, a serious accident or a problem may occur. Therefore, by generating a spare dispersion value, the problem that the control cannot be performed is avoided. be able to.

  Referring to FIG. 3, the control target terminal 50 to which access is restricted includes a control unit 51, an input / output unit 52, a storage unit 53, a display unit 54, a secret key authentication unit 55, a user information management unit 56, and a control target unit. 57.

  Unlike the information providing server 40, the controlled object terminal 50 to which the access is restricted does not store the electronic information to which the access is restricted, and therefore does not have the equivalent to the content management unit 47 provided in the information providing server 40. . Instead, a control target unit 57 to be controlled such as driving and communication of the control target terminal 50 is provided. The control target unit 57 is, for example, a door opening / closing unit or an engine starter unit if the control target terminal 50 is an automobile, a drive motor if a drone, or a communication setting or the like for IoT devices or communication routers. And a communication control unit.

  The method of electronic authentication of the user at the control target terminal 50 is basically the same as the electronic authentication of the user performed by the information providing server 40. That is, a user who wants to access the control target terminal 50 first registers personal information such as a name and a mail address with the user terminal 10. At this time, when the user terminal 10 and the control target terminal 50 can directly communicate with each other via the network 60, the user terminal 10 directly registers with the control target terminal 50.

  Although not shown in FIG. 3, a relay server provided by the operating company of the control target terminal 50 may be provided between the user terminal 10 and the control target terminal 50. In this case, it is also possible to provide a screen for user registration on a Web site provided by the relay server, and to set a my page in accordance with the user registration.

With or without the relay server, the personal information of the user transmitted at the time of registration is registered in the user information management unit 56 of the control target terminal 50.
Since it is not always necessary to input a user ID and a password to start communication between the user terminal 10 and the control target terminal 50, the user information management unit 56 registers a password from the user as necessary according to the embodiment. In response, the user ID is issued.

  The secret key authentication unit 55 performs electronic authentication of a user who wants to access the control target unit 57 of the control target terminal 50 whose access is restricted. When receiving an access request from the user to the control target unit 57, the secret key authentication unit 55 requests the user terminal 10 to transmit authentication information. On the other hand, when the authentication information is encrypted from the user terminal 10 using the restored secret key and transmitted, the secret key authentication unit 55 decrypts the received authentication information with the public key of the user terminal 10 obtained in advance, and performs authentication. When the user information matches the authentication information included in the personal information managed by the user information management unit 56 in advance, the electronic authentication of the user is performed.

  At this time, as described above, when generating the authentication information at the user terminal 10, the identification information of the shared value provider used to restore the secret key required for encryption is used as the authentication information. May be included. In addition, whether or not the identification ID of the specific variance value provider in which the reception prohibited state is set is included in the determination of the validity of the user is the same as the content described for the information providing server 40.

  In one embodiment, the secret key authentication unit 55 checks the identification ID of the information provider 20 and / or the preliminary information provider 30 included in the received authentication information, and checks the information provider 20 and / or Alternatively, if the direct identification ID is input from the preliminary information provider 30 and the identification ID included in the received authentication information does not match the directly input identification ID, the electronic authentication of the user terminal 10 is not performed. That is, since the user who has the information provider 20 and / or the preliminary information provider 30 that stores the shared value used for restoring the secret key is considered to be a legitimate user, the secret key authentication unit 55 Requesting the user to directly input the identification ID from the information provider 20 and / or the preliminary information provider 30 that stores the shared value used for restoring the secret key.

  For this reason, the control target terminal 50 has an input terminal for direct input from the information provider 20 and / or the preliminary information provider 30 and a short-range wireless communication unit. Conversely, the configuration may be such that the variance value is stored in the information provider 20 or the preliminary information provider 30 according to the input means of the control target terminal 50 to be controlled.

When the control target terminal 50 is a car, for example, the user terminal 10 may be a smart key of the car, and a configuration in which a driver's license configured to have a short-range wireless communication unit may be the information provider 20 is also possible. In this case, since the engine is not started without a driver's license, unlicensed driving and non-license carrying can be prevented.
By adopting such a configuration, the electronic authentication of the user becomes more strict, and the falsification prevention system 2 with high security, in which spoofing and the like are less likely to occur, is provided.

  Further, in the case of the control target terminal 50, a problem may occur if all the controls are released. For example, in the case of a car, a user who has a high potential for an accident such as an elderly person may be limited in the driving range or limited to a car equipped with safety equipment in the future. Further, in the case of a drone, a no-fly area is also set, so that there is a possibility that the use or the restriction of the flight area may be restricted depending on the user's qualification.

  Therefore, in one embodiment, at the time of registration of the user's personal information, metadata such as age and qualification related to the user's personal information is stored together, and the user is electronically authenticated by the secret key authentication unit 55. At this time, based on the metadata of the user-specific authentication information stored in the control target terminal 50 in advance, the control of the control target unit 57 is subjected to a specific restriction, and then the user terminal 10 is electronically authenticated.

  The input / output unit 52 receives various kinds of information such as personal information, electronic information, and authentication information from the user terminal 10 via the network 60, and sets the rotational speed of the motor of the control target unit 57 and communication control setting information. And communication means for transmitting the information. In the case of performing direct information input from the information provider 20 or the preliminary information provider 30 at the time of electronic authentication, a terminal for these connections and communication means such as short-range wireless communication are provided.

The storage unit 53 stores a control program for controlling the control target terminal 50 itself, in addition to the user's personal information and electronic information transmitted from the user terminal 10.
The display unit 54 includes a display unit that displays the status of the control target unit 57, a comment for the user, and the like.
The control unit 51 controls each component of the control target terminal 50 to perform the above function.

FIG. 4 is a flowchart illustrating a method for accessing electronic information of a user terminal according to an embodiment of the present invention.
FIG. 4 shows that the user terminal 10 stores in advance electronic information whose access is restricted. After generating a secret key necessary for accessing this electronic information, a shared value is generated and the user terminal 10 and the information provider 20 or It is assumed that the information is stored in the preliminary information provider 30.

Referring to FIG. 4, a user who wants to access electronic information whose access is restricted issues a dedicated application of the user terminal 10 in step S <b> 405 and issues an access request to the electronic information. The dedicated application is downloaded in advance from the server that provides the dedicated application, and controls the electronic authentication when accessing the electronic information whose access is restricted, as well as generating the secret key and generating the shared value. It is a configured program.
When the user terminal 10 receives a request to access electronic information in step S410, the user terminal 10 requests the user to input a variance value in step S415.

  On the other hand, the user inputs the share value to the user terminal 10 using the information provider 20 and / or the preliminary information provider 30 storing the share value necessary for the secret key recovery (step S420). At this time, when the information provider 20 and / or the preliminary information provider 30 are a USB memory or a memory card, they are directly connected to the connection terminal of the user terminal 10; Enter the variance value in 10. When the variance value is input as an image such as a two-dimensional barcode, the variance value is read out by image processing after the image is captured by photographing with a camera or the like of the user terminal 10. The user terminal 10 acquires the identification ID of the information provider 20 and / or the preliminary information provider 30 that provides the variance value together with the variance value.

  The user terminal 10 determines whether the acquired ID is the ID of the preliminary information provider 30 (Step S425). Whether or not the acquired ID is the ID of the preliminary information provider 30 can be determined by referring to a table managed by the variance value information management unit 16 and confirming a flag corresponding to the acquired ID. When the acquired identification ID is the identification ID of the preliminary information provider 30, the user terminal 10 changes the value of the flag of the information provider 20 substituted by the preliminary information provider 30 and sets the reception prohibition ( Step S430).

  If all of the identification IDs acquired in step S425 are the identification IDs of the information provider 20, the user terminal 10 determines whether or not reception prohibition is set for the identification ID of the information provider 20 in step S435. I do. When the reception prohibition is set for the identification ID of the information provider 20, the electronic authentication of the user is not performed, and the process is terminated. If acceptance prohibition is not set for the identification ID of the information provider 20, the user terminal 10 restores the secret key by combining the sharing value in step S440.

  Next, in step S445, the user terminal 10 performs electronic authentication of the user and approves the user's access to the electronic information. In the electronic authentication, for example, if the shared value obtained by restoring the secret key is correctly used in combination with the user terminal 10 and the information provider 20 for which reception is not prohibited, the user is authenticated as an authorized user. You may. In one embodiment, the restored private key is used to decrypt the private key previously encrypted with the public key, and the electronic authentication of the user is performed based on whether the restored private key matches the decrypted private key. .

After the electronic authentication, the user can access the electronic information and freely browse and revise it. Even if the electronic information whose access is restricted has been encrypted with the public key in advance, the electronic information can be decrypted with the restored private key, and thus can be browsed and revised in the same manner.
In step S450, the access to the electronic information ends, and the dedicated application ends. At this time, the dedicated application encrypts the electronic information viewed or revised by the user with the public key again and saves it in the storage unit 13, and deletes the dispersion value acquired for the private key restoration and the restored private key. The process is terminated so that it cannot be seen by a third party. The information provider 20 and / or the preliminary information provider 30 connected through the connection terminal are detached and stored separately from the user terminal 10.

FIG. 5 is a flowchart illustrating a method of accessing electronic information of an information providing server according to another embodiment of the present invention.
In FIG. 5 as well, electronic information whose access is restricted is stored in advance in the information providing server 40. After a secret key required for accessing this electronic information is generated, a shared value is generated and the user terminal 10 It is premised that the information is stored in the body 20 or the preliminary information provider 30 and that the user logs in the information provider server 40 and the user terminal 10 and the information provider server 40 can communicate with each other.

Referring to FIG. 5, a user who wants to access electronic information whose access is restricted starts a dedicated application of the user terminal 10 in step S505, and subsequently requests access to the electronic information (step S510). .
An access request to the electronic information whose access is restricted is transmitted to the information providing server 40, and the information providing server 40 transmits an authentication information request to the user terminal 10 in response thereto (step S515).

Upon receiving the authentication information request, the user terminal 10 requests the user to input a variance value (step S520).
On the other hand, the user inputs the share value to the user terminal 10 using the information provider 20 and / or the spare information provider 30 storing the share value necessary for the secret key recovery, and inputs the share value to the user terminal 10. The flow from the determination as to whether the preliminary information provider 30 has been used and whether the information provider 20 has been set to the reception prohibited state until the secret key is restored (steps S525 to S545) is shown in FIG. 4 is the same as steps S420 to S440 shown in FIG.

  Next, the user terminal 10 encrypts the authentication information with the restored secret key and transmits it to the information providing server 40 (step S550). The authentication information is any item or a combination of a plurality of items selected in advance from the personal information of the user registered in the information providing server 40 in advance.

  The information providing server 40 that has received the authentication information encrypted with the restored secret key decrypts the authentication information with the public key of the user terminal 10 that has been received and stored in advance from the user terminal 10 (step In step S555, it is determined whether the decrypted authentication information matches the authentication information in the personal information of the user registered in advance (step S560). If the two pieces of authentication information match, the user who transmitted the encrypted authentication information can determine that the correct authentication information is stored and that the correct private key that is a public key pair can be restored, and that the information The providing server 40 performs electronic authentication of the user, assuming that the user is a legitimate user (step S565). On the other hand, if the two pieces of authentication information do not match, the information providing server 40 does not perform the electronic authentication of the user and ends the process because there is a possibility that the source of the authentication information may be impersonated by a third party (step S570). .

  After the electronic authentication, the user can download the necessary electronic information, browse and revise it. The important electronic information is preferably stored in an encrypted form. In the embodiment, the key used for the encryption is a public key of the user terminal 10 or a public key of the information providing server 40. I do. If the electronic information is encrypted with the public key of the user terminal 10, the electronic information is downloaded to the user terminal 10 as it is and decrypted with the restored private key to access the electronic information so that the user can view the electronic information. become. On the other hand, when the electronic information is encrypted with the public key of the information providing server 40, the electronic information is once decrypted with the secret key of the information providing server 40, and then encrypted with the public key of the user terminal 10 and then the user terminal. Download to 10 In any case, since the electronic information is transmitted after being encrypted, falsification by a third party can be prevented.

  When the processing such as browsing or revising the electronic information is completed, the user terminates the access to the electronic information (step S575). If the information provider 20 or the preliminary information provider 30 for obtaining the variance value is connected, Remove these. At this time, the variance values other than the variance value stored in the user terminal 10 are deleted. Further, the electronic information that needs to be updated due to revision or the like in step S575 is transmitted to the information providing server 40 after being encrypted, and is updated by the information providing server 40.

FIG. 6 is a flowchart illustrating a method of accessing a control target terminal according to another embodiment of the present invention.
FIG. 6 is a diagram showing the basic flow of electronic authentication except that the access target is a control target terminal 50 whose access is restricted instead of the electronic information stored in the information providing server 40 whose access is restricted. This is the same as the content described in 5.

  However, since the control target terminal 50 is provided with a function different from electronic information, such as having a drive unit and requiring reliability and security in communication control, there may be variations in electronic authentication. .

  As one of the modifications, not shown in FIG. 6, in step S665 of performing the electronic authentication in FIG. 6, the control of the control target terminal 50 is performed based on the metadata stored together with the user's personal information registration. The electronic authentication of the user terminal 10 may be performed after adding a specific restriction. As a result, it is possible to limit the operation range of the user to the control target terminal 50, limit the application, and limit the communication control setting items.

  As another modified example, which is also not shown in FIG. 6, before the step S665 of performing the electronic authentication of FIG. A request for direct information input from the body 20 or the preliminary information provider 30 may be requested, and if correct information input is obtained, electronic authentication may be performed in step S665. As a result, a determination is made that the user who is trying to access the control target terminal 50 is a user having the correct variance value, and the legitimacy of the user is more strictly performed. With such a configuration, theft due to a relay attack of the vehicle can be prevented.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to the above-described embodiments, and various changes can be made without departing from the technical scope of the present invention. It is possible to

1, 2 Tamper prevention system 10 User terminal 11, 21, 31, 41, 51 Control unit 12, 22, 32, 42, 52 Input / output unit 13, 23, 33, 43, 53 Storage unit 14, 44, 54 Display unit Reference Signs List 15 secret key generation unit 16 shared value information management unit 17, 45, 55 secret key authentication unit 20 information provider 30 preliminary information provider 40 information provision server 46, 56 user information management unit 47 content management unit 50 control target terminal 57 control Target part 60 Network

Claims (10)

A user terminal that accesses electronic information to which access is restricted or a control target terminal to be controlled for which access is restricted, and an information terminal that can provide electronic information to the user terminal and is electrically separable, or At least one information provider including at least one of an information medium for providing information that can be captured by a user terminal, captured as an image, and extracted by image processing, and at least one preliminary information provision as a spare for the information provider A tamper prevention system in electronic authentication having a body,
The electronic information is stored in the user terminal, or an information providing server connected to the user terminal via a network,
Each of the user terminal, the information provider, and the preliminary information provider is different from each other and is used to restore a secret key required for electronic authentication at the time of accessing the electronic information or the control target terminal. Holding the variance value,
The secret key is restored at the user terminal by combining a share value stored by the user terminal with a share value provided by the information provider and / or the preliminary information provider,
When the user terminal is provided with a shared value from the preliminary information provider at the time of restoring the secret key, after the next time the private key is restored, the user terminal substitutes the shared value from the information provider substituted by the spare information provider. A falsification prevention system in electronic authentication, wherein a rejection prohibited state in which provision is not accepted is set.   When the user terminal accesses the electronic information stored in the information providing server, or when accessing the control target terminal, the information providing server or the control target terminal is encrypted by the secret key from the user terminal. Received authentication information, decrypts the authentication information with a public key stored in the information providing server or the control target terminal, and stores user specific authentication information stored in the information providing server or the control target terminal in advance. 2. The falsification prevention system in electronic authentication according to claim 1, wherein the electronic authentication of the user terminal is performed when the user terminal matches.   When the user terminal accesses the control target terminal, the control target terminal, if the decrypted authentication information matches the user-specific authentication information stored in advance in the control target terminal, 3. The electronic authentication of the user terminal according to claim 2, wherein a specific restriction is imposed on control of the control target terminal based on metadata of user-specific authentication information stored in the control target terminal. Falsification prevention system in the described electronic authentication.   Each of the user terminal, the information provider, and the spare information provider holds a unique identification ID, and the user terminal provides the information provider or the spare that provides a shared value when restoring the secret key. The electronic authentication according to any one of claims 1 to 3, wherein an identification ID of the information provider is acquired, and it is determined whether or not it is the preliminary information provider that provides a variance value. Tamper prevention system.   5. The user terminal according to claim 1, wherein, when receiving an input of an instruction to cancel the reception prohibition state from a user, the user terminal is set to be able to restart the reception of the provision of the variance value from the information provider. 2. A falsification prevention system for electronic authentication according to claim 1.   The authentication information includes an identification ID of the user terminal, the information provider and / or the preliminary information provider that provides a shared value used when the secret key is restored, and the information providing server or the control target terminal includes: 5. The falsification prevention system according to claim 4, wherein when the authentication information includes a specific identification ID, electronic authentication of a source of the authentication information is not performed.   The control target terminal confirms the identification ID of the information provider and / or the preliminary information provider included in the received authentication information, and the information provider and / or the preliminary information having the confirmed identification ID Receiving an input of a direct identification ID from a provider, and when the identification ID included in the received authentication information does not match the directly input identification ID, the electronic authentication of the user terminal is not performed. The falsification prevention system in the electronic authentication according to claim 6. Based on Shamir's threshold theory, n different variances (n is a natural number) are generated based on the Shamir's threshold theory, and at least k (k is a natural number) of the n variances are calculated. The secret key can be recovered using the above equation, and n and k satisfy a relational expression of n> k ≧ 2;
Among the n share values, at least k share values initially used for the recovery of the secret key are stored in the user terminal and the information provider one by one, and the remaining share values are stored in the spare The falsification prevention system in electronic authentication according to any one of claims 1 to 7, wherein the information is stored one by one in the information provider.   The information medium is a printed matter on which information created by a two-dimensional barcode or a digital watermark technique is printed, or an electronic apparatus including a display device capable of providing information created by a two-dimensional barcode or a digital watermark technique as an image. 9. The falsification prevention system in electronic authentication according to claim 1, wherein The electronic information to which the access is restricted is electronic information having high importance in the user terminal or the information providing server,
The important electronic information includes at least one of a contract, a copyrighted work, and personal information,
10. The control target terminal includes at least one of a car, a drone, a smart maker, an IoT device, a communication router, an IoT device control terminal, a robot, and an artificial satellite. The falsification prevention system in the electronic authentication according to any one of the above.

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